Casting Doubt On the Hawkeye Ball-Calling System 220
Human judgment by referees is increasingly being supplemented (and sometimes overridden) by computerized observation systems. nuke-alwin writes "It is obvious that any model is only as accurate as the data in it, and technologies such as Hawkeye can never remove all doubt about the position of a ball. Wimbledon appears to accept the Hawkeye prediction as absolute, but researchers at Cardiff University will soon publish a paper disputing the accuracy of the system."
Why not use... (Score:5, Insightful)
Why not use a radio transmitter in the tennis ball (or soccer ball or whatever) to record its exact position? I am certain this has been discussed and I wouldn't be surprised if it's already in use. The article's "Hawkeye" just works by optical analysis.
Why not, it works for shopping carts (Score:2, Funny)
If you leave the store parking lot, one of the wheels locks.
Re:Why not, it works for shopping carts (Score:4, Funny)
So if one of the players tries to steal a tennis ball, they won't get very far?
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Unfortunately, for my local supermarket, "leaving the store parking lot" is defined as entering the store.
Re:Why not, it works for shopping carts (Score:5, Funny)
Re:Why not use... (Score:5, Informative)
Why not use a radio transmitter in the tennis ball (or soccer ball or whatever) to record its exact position? I am certain this has been discussed and I wouldn't be surprised if it's already in use. The article's "Hawkeye" just works by optical analysis.
It's been tried in soccer. The latest attempts were prior to the last couple of World Cups IIRC, but the systems were plagued with problems, not the least of which was the survival of the transmitter.
http://www.gizmag.com/go/2790/ [gizmag.com]
Re:Why not use... (Score:5, Interesting)
Further to that, if the transmitter can't survive in a soccer ball (where a well-struck shot probably moves around 120-130 kph) then there's no way it will handle travelling over 200 kph after a serve, followed by a (at least) 100 kph forehand return (a net >-300 kph in a fraction of a second!).
Also, a radio transmitter cannot account for the distortion of a ball upon impact, which will depend on velocity, angle of rotation, angle of impact, surface being played on, etc etc etc...
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Further to that, if the transmitter can't survive in a soccer ball (where a well-struck shot probably moves around 120-130 kph) then there's no way it will handle travelling over 200 kph after a serve, followed by a (at least) 100 kph forehand return (a net >-300 kph in a fraction of a second!).
Red flag! (Oh god. Now I really want to see someone try that.)
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Also, a radio transmitter cannot account for the distortion of a ball upon impact
I seriously doubt that an umpire can.
Hawkeye's also being used in snooker now, and it actually looks very accurate. The refs always re-spot the ball at least 2 inches away from the spot where it was, and I don't see why they're not using this more often.
Honestly, even if the Hawkeye system is off by a few millimeters, if I were a pro tennis player then I'd rather have a call which is at most 3mm off than being called by an umpire who maybe wasn't paying close attention and calls whatever he thinks is righ
Re:Why not use... (Score:5, Interesting)
With tennis balls, I imagine there would be problems with balance and the response of the ball. Especially with such a small ball, mounting a rugidtized radio transmitter (a ball probably has to go through 20gs or something) would probably mess with the balance and how the ball deforms. Not to mention, unless you can mount the system directly in the center of the ball, then you still have a margin of error the diameter of the ball. I imagine that would be fairly significant amount of error in tennis (perhaps on the same level as this Hawkeye system?) when calling the lines.
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wouldn't this be a good use for RFID tags/? they should be tough enough to handel it
Re:Why not use... (Score:5, Interesting)
Triangulation of radio signals is not accurate enough to give sub-centimeter accuracy and the added mass to the tennis ball would probably cause the players to have some objection to adding a radio transmitter into the ball.
The claim that the Hawkeye system gives an average of about four millimetres of error seems somewhat reasonable, given that we're getting accuracy greater better than two centimetres on detecting objects with a single camera with optics as large as the last segment of a typical pinky. (FWIW, here's a short demo [youtube.com] of what we're working on for our autonomous underwater vehicle [etsmtl.ca])
However, the suggestion to display the error range for a particular shot and leaving the final decision to a human from TFA is quite reasonable and is how it should be. Blindingly trusting technology or discarding it altogether is unreasonable.
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...leaving the final decision to a human from TFA is quite reasonable and is how it should be.
No it isn't, it's ridiculous. On what basis is an umpire supposed to over-rule a machine with 4mm accuracy? True, the machine may be "wrong" from time to time but by trusting a machine you create a deterministic rule set which is completely neutral. It is precisely the fact of removing a human from the equation that makes Hawkeye so useful and so MacEnroe proof.
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Blindingly trusting technology or discarding it altogether is unreasonable.
I disagree. Since this is a game, it seems to me the most important thing is that the rules are applied consistently and impartially. Accuracy may be the goal of making the rules, but once the rules are set, I'm much more concerned about the consistency and impartiality.
They played tennis for quite a long time without the technology, and so it's evident that discarding it altogether wouldn't be so bad. Accuracy isn't really the issue. You could decide all disputes with the roll of a 12-sided die, and i
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Wimbeldon, IIRC, has a limit of 3 appeals. Just as an example.
Read The Friendly Article (Score:3, Informative)
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The issue isn't whether its infallible, but whether its more accurate then a human. If it is, then we should replace umpires with the Hawkeye systems. Will there be bad calls? Sure. But they will happen less.
Re:Why not use... (Score:5, Interesting)
I envision something that looks like a big LCD touch screen (but more durable). Every time something made contact with the active surface, a record of the ball's "footprint" could be recorded (and even temporarily displayed wherever it touched the surface). That would allow for highly precise measurement of the ball's landing position, and it wouldn't need to incorporate any new materials into the ball itself. The active surface would only need to be in the out of bounds area, and even then, it would only need to be half a foot wide in order to cover the important zone where the ball's landing position is questionable.
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We could call such a surface "Wet Paint" and use it whenever we need to determine if contact was made between the "Wet Paint" and another object.
Re:Why not use... (Score:4, Funny)
"the chalk flew up"
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Yeah, that'll work. Just like in soccer where there's 5+ hands from both sides in the air claiming it was their ball in every dubious corner/throw-in situation.
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http://en.wikipedia.org/wiki/John_mcenroe [wikipedia.org]
Although I understand the confusion caused by the fact my gp comment is modded insightful!
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Re:Why not use... (Score:4, Insightful)
Fox tried to do that with hockey back in the 90s in order to make the puck easier to see on TV (personally, I've never had a problem seeing the puck). The Glow Puck was horrible. When there was a jam up in the corner, it would literally be bouncing all over the screen. It also changed the way the puck performed on the ice. Because of the electronics and battery inside, they couldn't freeze the puck like they normally do, causing it to bounce a lot more and not slide on the ice as easily.
In a hollow sphere like a tennis ball, how would you keep the dynamics of the ball the same as they are when you add a transmitter to it? If you adhere it to the side, the ball will be off balance. If you create some internal structure/support to keep it centered, you change the deformation during a bounce/hit.
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Could someone explain to me how this would be any more precise than high-quality optical analysis? Usually, in the slo-mo replay recorded by even the *average* quality cameras for TV audiences, you can almost always tell whether a ball was in or out. Make that higher quality cameras with a higher frame rate, and optical analysis seems like a very good way to do it, to me. It is, after all, what human umpires do.
Re:Why not use... LASERS! (Score:4, Funny)
It doesn't have to be perfect (Score:2, Interesting)
The decision of which system to use: human, computer, human with computer check, computer with human check, committee vote, or what-not should be based on which has the lowest uncorrected error rate within limited time constraints.
This assumes there is another method, such as post-analysis of videotape, that can find almost all uncorrected errors or at least give some good indication of the uncorrected error rate.
Re:It doesn't have to be perfect (Score:5, Funny)
This assumes there is another method, such as post-analysis of videotape, that can find almost all uncorrected errors or at least give some good indication of the uncorrected error rate.
Another method would be to use Radar instead of Hawkeye. Probably faster and more efficient as well.
(obscure reference).
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In the event of a tie between the two systems, perhaps a Honeycut system to break the tie.
O RLY? (Score:4, Funny)
You Pierce me with your wit! It Burns! When you finally drag out your Winchester and kill me, you'll have to bury me in a field fit for a Potter because I can't afford anything better.
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How do you take the measurements to compare?
The only solution (Score:5, Funny)
And ultra-accurate GPS like system that tracks the position of balls in nanosecond detail. They can call it Your Object Universal Remote Movement Observance Mechanism, or YOUR MOM for short.
Other applications? (Score:2, Interesting)
Can this be applied to something useful. You know besides whether or not someone was out in a game of tennis?
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You're a guy reading slashdot by yourself on a saturday night. It doesn't take any special technology to know the answer to that question.
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Re:Other applications? (Score:5, Funny)
Yes, some people also want to use Hawkeye for some decisions in cricket, the sport that first used it. However the margin of error is far greater (approximately +- 2 inches) in cricket as the cameras have to be a lot further away due to the size of the pitch.
Also Hawkeye finds it hard to pick up swinging, seaming and spinning balls. Basically anything that deviates off its theoretical trajectory either in the air or off the playing surface. Both of which are vital in the LBW decisions where the TV companies and doubtless the Hawkeye people would want to see it used.
Obviously cricket is a far more useful game than tennis so does this answer your question?
Re:Other applications? (Score:4, Insightful)
Yes, some people also want to use Hawkeye for some decisions in cricket, the sport that first used it. However the margin of error is far greater (approximately +- 2 inches) in cricket as the cameras have to be a lot further away due to the size of the pitch.
The other key difference in cricket is that Hawkeye is used to predict where the ball would have gone had it not hit a pad, whereas in tennis it only needs to say where the ball actually was.
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Obviously just tracking a ball is a more definite science than the prediction of something that didn't happen (but could have). Especially as anyone who knows about cricket will tell you is that the path of the cricket ball is 'mysterious'.
I once heard a cricket commentator interviewin
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Can this be applied to something useful. You know besides whether or not someone was out in a game of tennis?
Must of the technology that underlies Hawkeye was originally designed as a missile tracking system. Although personally I think sports are far more worthwhile than warfare.
major league base ball umpires union does not like (Score:2)
major league base ball umpires union does not like systems like this and systems like that are not 100% also there stuff that is hard to make calls that can be 100% done by a bot.
http://query.nytimes.com/gst/fullpage.html?res=9406E6DE1F39F933A15754C0A9649C8B63 [nytimes.com]
http://query.nytimes.com/gst/fullpage.html?res=9D00E1D61130F933A1575AC0A9649C8B63 [nytimes.com]
http://findarticles.com/p/articles/mi_m1208/is_24_227/ai_103378465 [findarticles.com]
http://en.wikipedia.org/wiki/QuesTec [wikipedia.org]
Re:major league base ball umpires union does not l (Score:2)
The New York Times references are several years old. The Wikipedia article you mention says the controversy has died down and the system has brought the intended benefits.
I wish they would just use an automated system in all the parks instead of relying on the umps. I also wish they would use a standard strike zone, instead of one that changes based on the batter. It'll never happen, though.
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Review? are you kidding?
Do you know how many "close" pitches there are in an average baseball game? I think they were working on lowering the average time of a game, this would shoot it way back up.
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(Really, I hadn't thought of that. Wow. That'd ruin it. I figured that that system had worked well for that game.) I played in college and actually wanted to consider an attempt at a career before admitting to myself how unrealistic it was and so I have a love affair with baseball so I'm at a loss of how we can automated the ref
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The only way to do it would be to develop the system so that is as accurate as possible. Sensors in the uniforms to measure the strike zone, sensors in the bat to determine if they check the swing, etc.
If you can't get it to the same accuracy or better than an umpire, forget it.
After doing that, you'd have to disallow reviews. That would speed up the game. The umpire NEVER changes his call when anyone argues with him, so people could storm out and have just as futile a conversation with the umpirebot 2000
Re:major league base ball umpires union does not l (Score:4, Insightful)
I'm confused. Why would umpires oppose a technology that can automate the refereeing of a game? It just doesn't make any sense.
Anonymous Coward (Score:3, Insightful)
They're reproducing stuff that's already known. Yes, Hawkeye can be inaccurate. However, it's MORE accurate than linesmen and certainly the chair umpire. That's why it's used as the definitive word.
I'd certainly prefer it to be used otherwise - the best way would be to give the chair umpire the information from HawkEye and then let him decide whether to use it or not at any given time, properly educated about the types of errors the machine can make - but that wouldn't be as flashy, would it. So the advertisers wouldn't go for it.
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Re:Anonymous Coward (Score:5, Insightful)
If it had, it would be simple to reduce the number of cameras to three, and boom - perfect position.
That's obviously not how it is.
And of course does the number of cameras increase the precision of the computed position - the principle
is exactly the same as for GPS, where more satellites are better as well.
Using a certain fitting method (least squares, least absolutes etc.) has nothing whatsoever to do
with something like "complementing the equations", that's just necessary because no measurement is perfect -
You are arguing that multiple measurements do not increase the accuracy of a computed average because there
are multiple averaging algorithms to choose from.
Bullshit.
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Sorry, but you don't know what you're talking about.
Any system of equations with more equations than unknowns is called overdetermined. If you have 5 cameras and 3 coordinates, that leads to an overdetermined system.
The accuracy of the cameras matters, because if the re
addendum (Score:2)
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Using a certain fitting method (least squares, least absolutes etc.) has nothing whatsoever to do with something like "complementing the equations"
I don't know what you mean by complementing the equations.
Neither do I, that's an expression you introduced, and the reason why I put it in quotation marks.
You are arguing that multiple measurements do not increase the accuracy of a computed average because there are multiple averaging algorithms to choose from.
Precisely. These multiple averaging methods give different answers. Which one is right? There isn't one. In particular, none of them is more accurate than a human. Just different.
Fascinating. I regularly make measurements in the micrometer scale using a microscope, and easily increase the precision of my results by repeating them.
So I should just trust my gut feeling, statistics be damned? Thanks, that'll really speed up my work.
I'm really not convinced that I am the one with no clue...
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Look, statistics is much more complicated than averaging. Do you know where the averaging rule that you use comes from? It's the maximum likelihood estimator [wikipedia.org]: It's a function of the observations which is obtained under certain assumptions on the physical process (which in your case would typically be a Gaussian distribution of errors, all ind
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Combining observations isn't arbitrary, its based on prior knowledge of the underlying statistics and measurement methods. If the multiple measurements are identical with normally distributed error, for example, the mean can be used. If the measurement is subject to random catastrophic failure (e.g. bit flipping), then the median is a good choice. In the Bayesian method you form a composite probability distribution by combining conditional or joint probabilities. In fact, if you do it wrong, you can mak
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It's also based on the type of loss function being used, which is arbitrary, and many people would say that prior knowledge, being subjective, is a classic example of arbitrariness.
Take a simple example, a Kalman filter of a single constant value with a perturbation and a trivial observation model. Your filter has two parameters, for the variance of the perturbation, and the
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>Precisely. These multiple averaging methods give different answers. Which one is right? There isn't one. In particular, none of >them is more accurate than a human. Just different.
I have no idea what you're on about.
We know there only one true answer so obviously the accuracy is different. The human usually misses the correct location by measure X and the computer misses by meausre Y. They have different accuracy.
Re:Anonymous Coward (Score:4, Informative)
If the errors are random and follow a normal distribution (two big ifs, I admit) then even in one dimension, the error is reduced by a factor of 1/sqrt(N) where N is the number of measurements.
The same general idea applies to higher dimensions. If you can avoid systematic errors then the more measurements you take, the more accurate your final result will be. If you are interested in the gory details of the higher dimensional case, you should take a look at singular value decomposition [wikipedia.org].
Re:Anonymous Coward (Score:5, Informative)
Because we are dealing with reality as well - where no measurement is perfect.
Geometrically, three sats indeed are enough, but in reality:
More measurements -> smaller error bars -> better position.
The alternative to more sats would be not to move and to take more measurements over time.
But that would render GPS useless for most applications
Additional trouble with the "stay and wait" method: Those nasty satellites move over time,
introducing different errors that can not be eliminated as easily by simple averaging.
That's also why ultra precise GPS surveying records the satellite data and waits for the week it takes
to make the actual orbital data (as measured, and not just as predicted) available before computing
the position, thereby elimiating (well, at least reducing) another source of error.
In statistics, the only thing beating multiple measurements is even more measurements.
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Long answer: The ranges calculated in GPS are estimates, because the clocks in the receiver aren't very precise. A small offset in the timing can cause a large error in the calculated distance (if the clock is off by 1/1000th of a second, you're actually 200 miles away from where you think you are). This is why GPS usually uses 4 satellites. If the receivers all had ato
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Four dimensions.
In a GPS system the precise time is also a free variable to be determined from the satellite transmissions, so you need >=4 satellites.
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A system such as Hawkeye CANNOT BE MORE ACCURATE than humans.
Of course it can be, humans are not 100% accurate and even human eyes aren't 100% accurate.
From the link in the article, the Hawkeye system uses 5 cameras to compute the 3D position of the ball. That's an overdetermined system of equations, which cannot have a unique solution due to observation errors in the camera views.
That it's overdetermined doesn't matter since in the end the error of those combined non-unique solutions is still less than that of a non-overdetermined system of the same cameras.
So Hawkeye has to complement the equations with an ARBITRARY rule, eg least squares, and this arbitrariness makes the Hawkeye estimate neither more accurate nor less accurate than humans, just different. FYI, there are plenty of other arbitrary rules that work, eg least absolute errors, maximum entropy, etc.
That it uses an arbitrary rule says NOTHING about it being capable of more accuracy than a human. Accuracy is easy to determine (via experimentation if you wish) and claiming that we somehow magically can't measure it is idiotic. For exampl
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You're missing the point. Accuracy makes no sense unless you include the error criterion. Any estimation algorithm has an arbitrary error criterion, as do humans. Neither is more accurate than the other, they're just different estimation procedures.
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You're missing the point. Accuracy makes no sense unless you include the error criterion. Any estimation algorithm has an arbitrary error criterion, as do humans. Neither is more accurate than the other, they're just different estimation procedures.
No, talking about the size of the error makes no sense if you haven't specified a regularization criterion. Now choosing the criterion is essentially equivalent to choosing what the theoretical answer should be, so it's circular reasoning to claim that the resulting error would be smaller.
That's a silly argument because it basically says "nothing is better than a human because a human is no optimized for the problem" or "we can never determine what is better because we need to first determine what better is and there is more than one possibility." You can I'm assuming create a system that is in fact more accurate across all error criteria but that's a separate point. There already is an error criteria in place since human judges must somehow be chosen and evaluated. The computer system in f
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I believe the correct criterion is "whatever will convince the judge". It's certainly acceptable for judges to use mechanical props to improve their own ability to adjudicate.
In the mechanical system, what happens when the erro
Re:Anonymous Coward (Score:5, Insightful)
I'm willing to concede that you are talking theory at some level I don't fully grok. What I think you're completely missing in this discussion stems from your original statement that"system such as Hawkeye CANNOT BE MORE ACCURATE than humans", which does not seem to be possibly true by any standard definition of these words that I am familiar with.
You can talk about "error criterions" and odd offtopic tangents about targeting algorithms etc, but the bottom line is, your original statement is completely wrong.
You say "So Hawkeye has to complement the equations with an ARBITRARY rule, eg least squares, and this arbitrariness makes the Hawkeye estimate neither more accurate nor less accurate than humans".
That's both wrong and illogical. Yes, Hawkeye is estimating a solution, and using a "arbitrary" (again, this is utterly bizarre and incorrect word choice--the makers of Hawkeye have presumably done a great deal of testing to pick an algorithm, which is NOT arbitrary) method to estimate. However, if Hawkeye ESTIMATES the correct answer more often than a human judge then, Hawkeye is more accurate than a human judge. The methods it uses are really completely irrelevant to the final answer.
So in short, it seems that this is a discussion in your usages of "accurate," "error," "arbitrary," etc are different than the rest of the people in the thread.. Please let me know if I'm misinterpreting something though!
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By separating the "correct" answer from the human judge you are, I think, describing a subtly different game. The umpire matters fundamentally in the game, and cannot be ignored. Certainly, tennis would be rather different if every decision were mechanical.
When you refer to the correct answer, you're effectively claiming that no judge is needed since the answer already exists (in some kind of Platonic ideal) and can always be calculated in principle. If mor
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As the other poster implied, your first assertion is what the "point" is. Speaking of points, your last paragraph doesn't seem to have one, it basically says different problems have different equations and answers.
I would also suggest that an emprically derived 4mm error is demonstratably more accurate than any human and no amount of irrelevant math will change that. If what you and TFA are trying to say is, "i
Re:Anonymous Coward (Score:5, Insightful)
A system such as Hawkeye CANNOT BE MORE ACCURATE than humans. From the link in the article, the Hawkeye system uses 5 cameras to compute the 3D position of the ball. That's an overdetermined system of equations, which cannot have a unique solution due to observation errors in the camera views.
Luckily there's a 100+ year old discipline called statistics, and 60+ years of literature on tracking to help you out in these cases.
So Hawkeye has to complement the equations with an ARBITRARY rule, eg least squares and this arbitrariness makes the Hawkeye estimate neither more accurate nor less accurate than humans, just different. FYI, there are plenty of other arbitrary rules that work, eg least absolute errors, maximum entropy, etc.
While I can't speak for the designers of the Hawkeye, in tracking there are very good reasons to choose one form of error minimization versus another. It only seems arbitrary because you are not informed on the subject, but there's plenty of free papers out there to read and discover.
To explain current methods, please start out with this paper [google.com], in particular Figure 2, you'll see that the sort of errors you get from a camera are indeed well fit by a Gaussian. While a camera's perspective transformation is not purely linear (and various forms of distortion make it also non-linear), a good camera with a decent lens estimating the ball location within a limited area is well approximated by a linear model (and you can characterize just how much the error is). Now, a bunch of cameras with a Gaussian error distribution in the image plane with a linear projection out into the world is still a Gaussian (with a transformed covariance matrix). You can then multiply the independent measurements from multiple cameras to get a better estimate. Add a time series to that and apply this recursively and you get a Kalman filter [unc.edu], something invented for aerial tracking and still in widespread use today. If something is good enough for missiles to intercept other missiles, it ought to be good enough for a tennis match.
If the linear approximation not good enough for you, you can use a Rao-Blackwellized Kalman filter. If that's still not good enough because you want to use another error distribution or non-linearizable dynamics, set up a particle filter with a whole lot of particles and enough CPU to simulate it. The point is that what you call arbitrary is a well studied field which is many decades old. You'd be best served by learning about it first before you cast away all that work. I'm not a "tracking" person, just a user of there work. When a field of science has done its job well enough that it has become common engineering, and you can go look up whatever you need in books, with all the derivations, caveats and tradeoffs laid out there for you to see, I would say that that field has done a pretty good job.
The whole media story around this paper is ridiculous. It's a paper from a social sciences department about how the public does not understand the fallibility of these machines due to noise. That's all this paper is about: Hawkeye has error. I hate to break it to the uninformed, but all measurement systems have error. From Galileo [wikipedia.org] to Gravity Probe B [wikipedia.org], your results can only be as accurate as your measurements, calculations, and statistical models will allow. You can decrease error with various methods, but you can never completely eliminate it. People should not be able to get out of high school without understanding accuracy on measurements, and some rudimentary statistics, but unfortunately our education system hasn't been able to reach that goal. As a result, the public doesn't understand error, and might come to believ
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Yes, and this discipline depends on something called decision theory [wikipedia.org], which in turn depends on an arbitrary choice of loss functions.
None of this matters one bit if these reasons are not compatible with the sporting rules in the problem at hand. To be pedantic, if the rules say that
Re:Anonymous Coward (Score:5, Insightful)
Just because an umpire is the final word doesn't mean that a system can't do better than him, That is because the umpire is in fact he trying to measure something with a right/wrong answer. Specifically the umpire is the person who decides if event X happened or not which means that the goal is to see if X happened or not (not to see if the umpire thought X happened or not). The umpire isn't an inherent part of the rules but simply a judge to determine if something specified in a certain rule happened or not. As a result it's a perfectly valid problem to predict this event X in a method that is better (ie: lower misclassification) than the umpire. Finding the winner in a horse raise is one example of where technology is more accurate despite the rules likely having a person originally be the final judge.
One problem is that sometimes one can't measure the true answer in some way so there is no way to truly measure accuracy for a problem. That is a valid problem however I have no clue if that or something else is the actual problem you're so concerned about (your posts are as clear as black mud). In this case there probably are more accurate systems of measuring the truth although these take excessive money, time or preparation. One could for example cover the ground around the line with wet paint (or some such) and then check for breakages, or simply cover the ground with pressure sensors. The article implies they can measure the accuracy of the system compared to the true impact point which means that one can devise experiments in which one can measure the truth of where the ball lands.
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As long as the equations are not determined from outliers then an overdetermined system can be made accurate - though one must take into account numerical instabilities. At the end of the day, such systems can easily be deemed empirically more accurate than human-reckoning, for this set of very narrowly defined requirements.
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Consistency, is more important than accuracy! (Score:5, Insightful)
Hawkeye and the like deliver a consistent result. It matters not at all if the ball is in by two Centimetres but is called out, provided that error is consistent throughtout the match.
If both players, or teams, are playing by the same margin of error, the contest is fair.
In cricket for instance, I would accept the computers call over umpires any day of the week!
Re:Consistency, is more important than accuracy! (Score:4, Interesting)
That is only true if you assume the two players are making the same level of mistakes. If both players are regularly hitting the same shots witht he same amount of error, yes everything will even out. But let's say player A can consistently serve and hit the ball to within 2 cm of the out line, but player B often misjudges and goes 1 cm over. In this case, having player A's shots consistently called 'out' or player B's shots consistently called 'in' would be consistent, but it would also make a major change in the outcome of the match. And not the type of change that gets statistically evened out over games played.
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The problem with line judges is that unlike Hawkeye, line judges have to see the landing point of tennis ball from pretty far away, and that tends to cause far worse judgment errors than with Hawkeye.
No system is 100% foolproof, but those with the least amount of errors will reduce problems with judgment calls by by a long way. In fact, that's why Major League Baseball might even implement a replay system to determine home run calls as early as August 2008, given the recent spate of inaccurate calls by umpi
Re: (Score:3, Interesting)
Hawkeye cannot 'hear' a snick to give a 'caught behind'.
the tv companies have a "snickometer" which puts up an analysis of the sounds picked up by a microphone in the stumps. Its only used for commentary. The umpire makes the decision himself
Hawkeye cannot (as far as I can tell) decide if a ball is caught or if the fielder let it slip through his fingers as he scoops it up the ground.
A good tv replay can show this but as cricket is a gentleman's game it is up to the fielder making the catch to say if he thinks he made a clean catch. There have been instances in test cricket where fielders have called back batsmen after the umpire initially gave them out.
Hawkeye cannot tell if a Leg Bye or simple bye was scored.
No but the umpire can, hawkeye finds it very hard t
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Except perhaps for the penultimate comment -
LBWs are not a small percentage of decisions, the appeals made to the umpires to decide are usually LBWs (catches are generally obvious and the umpire doesn't even have to rule).
Nonetheless the gp is talking nonsense, Hawk-eye usually just backs up the umpire showing that he came to the same conclusion in a second as the machi
Ummm.... (Score:3, Informative)
I've seen in Hockey and Football broadcasts the ability to track the ball or puck realtime thru some system inside the playing piece (puck or football.) It seems to work pretty decent to me.
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With hockey, I imagine that the puck is solid makes it simpler to ensure the integrity of the weighting of the puck after impact than it would be with a hollow tennis ball. Striking the relatively light and soft tennis ball to high speeds deforms the ball si
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This is an American website. If you want to be understood by the majority of visitors, you need to use the American terminology.
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It's certainly not used in NHL ice hockey. There used to be a "feature" in one of the network broadcasts of hockey games where they would add a "glow" around the puck to make it easier to follow on screen- this was done not using a tracker inside the puck, but was painted on digitally during the broadcast delay. Were a tracker to be put in the puck, the most significant use of it would be in deciding close goals where it isn't clear if the puck is over the line completely or not. No such technology is us
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FoxTrax sucked ass. It often lagged the puck by a second or so and did not significantly help find the puck. Plus, it just looked cheap and lame. It was abandoned after a couple seasons.
Summary Miseleading? No Wai! (Score:4, Informative)
For those that didn't care to RTFA, the study is in the journal 'Public Understanding of Science' and (gooly who would have guessed) doesn't have anything to do with the summary written. They argue that uncertainties in measurement that normally don't impact the layman now need to be presented in an understandable way. They worry that people will wrongfully become too trusting of the systems that do have appreciable error in rare circumstances.
To inject my own opinion on the matter, I've had a little bit of experience with Vicon motion capture systems which appear to use similar technology to the Hawkeye system. The main problem with the system (when it works) isn't any problem with accuracy or precision. In fact, it's awesome. The problem is that the output is a little noisy and suffers from occasional jumps and hiccups. With proper filtering these are eliminated and the output is amazing. I can only imagine the problem is much easier when you're tracking a single ball rather than tens of tiny reflective makers such as with the Vicon system.
Doesn't matter, as long as it is consistent (Score:2)
It doesn't matter how good, or even how bad the system is. As long as it cannot be shown to have a particular bias to a player, or the side of the court then it is automatically more fare than any existing judge.
period.It doesn't matter if it is even out my 5 centimeters, never mind having an error rate of less than half a centimeter.
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An overly generous or overly tight judge will inherently favor either risk taking or conservative players. Thus there will always be a bias.
Now the same could be said of umpires, but with umpires everyone understands the sorts of errors they introduce. The idea that the umpire could be wrong is freely discussed and lived with. As the article points out, systems like HawkEye usually foster the public perception that they are the absolute truth when in fact every physical measurement has a statistical e
Refereeing is by many considered PART of the game. (Score:5, Interesting)
For a system like Hawkeye to be useful, it doesn't need to be perfect. It just needs to consistently be more accurate and impartial than a referee can be.
Nor is it required for the system to be fully automatic and autonomic. Referees can sit in front of their monitors, observe the cameras from all angles, with any time slowdown, and ultimately come to a better decision than a single person could make while the ball buzzes past them at Warp 9.
But from the social aspect, one has to decide on what is the referee's role, and what kind of influence, if any, do we want to delegate to a computer. And that depends on the type of sport.
For non-interactive sports such as sprinting, an automatic system works very efficiently, and most people readily accept it as better than a human time tracker.
But for many GAME sports (soccer and boxing come to mind) many people consider that a referee is PART of the game rather than just an observer. As long as a referee is comparatively competent, and acts in good faith, he has the authority to judge events in the game, and while mistakes are unavoidable, they are considered part of the game as well.
I'm not sure why this position is popular in these kinds of sports. Maybe it's the whole "humans should be judged by humans and not machines" aspect. Or maybe it's because having a Review Comission in front of CCTV monitors be judging every little move just feels too 1984-rish for spectators and players alike. Or maybe its something else. But this is a rather popular feeling.
Depending on the features and benchmarks of the electronic system, it may or may not be more accurate than a human observer. In the long term, a joint human-computer analysis system would be certainly more accurate than a human referee alone, especially in team or high-speed sports. But one has to ultimately question, whether, by gaining mathematical precision, we lost some human touch of sport that makes it enjoyable to play and watch. Fun can't be generated with a mathematical formula. And sometimes sitting on the couch and thinking "OMG that referee is such a dumbass" is part of the fun as well.
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But one has to ultimately question, whether, by gaining mathematical precision, we lost some human touch of sport that makes it enjoyable to play and watch. Fun can't be generated with a mathematical formula. And sometimes sitting on the couch and thinking "OMG that referee is such a dumbass" is part of the fun as well.
Watched the Aussie Open or Wimbledon in the last couple of years? I, and most other observers, consider that Hawkeye makes the game more enjoyable, and whilst probably isn't 100% accurate, i
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>For non-interactive sports such as sprinting, an automatic system works very efficiently
The system (photo finish) used in sprinting isn't exactly automatic. A line scan image is taken of the finish line as the runners cross and a human looks at the image to determine in which frame the chest of a runner first appears.
Semantic argument (Score:2)
Applications of Hawkeye (Score:2)
I am not sure how many cameras are used in Tennis, but I am guessing they use at least 6 of them to triangulate which I believe produces an accuracy better than that a human can produce.
IIRC, Hawkeye was introduced in cricket to judge LBWs (Think of it as the ball hitting the batsman on it's way to the stumps). Now the rules say that any doubt must go in favour of the batsman, but obviously common sense prevails and umpires make a subjective decision on whether or not the ball is going on to hit the stumps.
Bias against technology (Score:2)
I am not sure why people put technology to higher standards than humans. TFA (yes! I read it!) says this:
Led by Professor Harry Collins and Dr Robert Evans, the team argues that such devices could cause viewers to overestimate the ability of any technological devices to resolve disagreement among humans. It also suggests that a more detailed understanding of how the device works could play a vital role in public education the benefits of which could spread to all technological decision making in the public domain.
I am not sure Hawkeye CAUSES people to think machines are infallible, but it's rather backwards where HAwkeye is assumed to be infallible BECAUSE people expect computers and machines to be correct 100% of the time. The potential for error by a computer is alien to most people (not least because people like my idiot CS teacher in school keep telling you that computers are 100% accurate and that they never
You cannot be serious! (Score:3, Funny)
That ball was on the line!
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Army brat, myself, but my first thought on reading the headline was along similar lines.
I couldn't for the life of me think of a reason why a Hawkeye [wikipedia.org] would need a system to call the ball when every other pilot in the Navy has to do it with the ol' Mk. 1 Eyeball.
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I completely agree. It really disturbs me that people accept as absolutely correct a cartoon image of where the ball landed. It's a cartoon for god's sake! I'd much rather see a high speed real image.