Possible to prove mathematically that the football spot was bad?

[Chestermiller]

In the 2016 Michigan vs Ohio State Football Game, the referee spotted the ball after 4th down with seconds to go in the game with what appeared to be a "bad spot." If not for this, Michigan would have won the game. On the next play, Ohio State scored a touchdown that won the game.

Would it be possible that photographic evidence exists to prove mathematically that the spot was bad? How much evidence would be required (such as camera angles, locations, etc.) to resolve this issue? Realistically, what would be the minimum amount of evidence required? Any estimate of the number of man-hours and other resources that would be entailed in seriously researching this?

 

[Andy Resnick]

Now, I have to disclose that my family is all OSU but my work colleagues are UM. Personally, I'm not into NCAA but care deeply about the Browns- I know from first-hand experience how frustrating 'bad' calls are.

Yes, it's possible to 'prove' where the ball should be spotted based on images- and there are enough cameras available already. It's also possible to prove, for example, when pass interference occurs based on images (ahem...). But the use of instant replay to 'correct' has to be balanced against the harm caused by constant interruptions of play, and there's a reason why some calls are not reviewable. I wonder if strenuous calls for more and more use of instant replay are in fact a projection of wishing for removal of all uncertainty in life.

 

[Comeback City]

Football games (or any sport) are not decided by one play... they're decided by the entirety of the game. It would waste far too much time to use instant replay on every single play, considering games already last so long. One bad call--- no matter how awful or momentum-changing--- will not decide a game.

But, yes, the photographic evidence certainly exists to place the ball accurately.

 

[Chestermiller]

Football games (or any sport) are not decided by one play... they're decided by the entirety of the game. It would waste far too much time to use instant replay on every single play, considering games already last so long. One bad call--- no matter how awful or momentum-changing--- will not decide a game.

But, yes, the photographic evidence certainly exists to place the ball accurately.

That's what I wanted to know.

 

[Chestermiller]

Why do you think it is that no one at Michigan's departments of Physics or Engineering has pursued this? Is it just that no one has thought of doing it? I would think that the Athletic department would be eager to fund a study like this.

 

[Comeback City]

@Chestermiller
To clarify, are you asking why they haven't looked into more efficient ways to review? Or just why they haven't looked into this one specific play in the football game?

 

[russ_watters]

I would assume that the football departments at major universities have every camera angle for every recent game in an archive. And the camera angles tend to be fixed. I would think if so inclined it would be easy to prove.

 

[sophiecentaur]

In many ways, the ideal thing wold be to have some 'intelligence' in the ball itself so that it could know its velocity and position at all times. Visual sighting is affected by the presence of bodies all over the vital areas of activity. A local hyperbolic positioning system using a suitable wavelength ( say 0.1m) could give all the information needed.
The problem would be (as it is with tennis, rugby and football) that only the higher league clubs could afford to run that sort of system.
Of course, the practice of arguing with and threatening match officials should be dealt with before any technical help that the Ref could use.
"Arguing with the ref? Back ten metres" sorts it out easily.

 

[fresh_42]

What is a bad spot? And was it 4th and inches or 4th and long?

 

[Chestermiller]

What is a bad spot? And was it 4th and inches or 4th and long?

In this case, it was first down by an inch.

 

[jbriggs444]

The important thing in a game, or, for that matter, in a court of law, is not that the decision is correct.

The important thing is that the decision is made and accepted. The acceptance part is what motivates at least an appearance of fairness and correctness.

 

[pinball1970]

In this case, it was first down by an inch.

They use camera technology now a lot in sports Tennis footy (soccer) rugby and cricket.

https://www.chroniclelive.co.uk/spo...news/video-referee-system-make-debut-14126254

https://www.nzherald.co.nz/sport/news/article.cfm?c_id=4&objectid=12164339

I think the reluctance in introducing them was a worry about how it would affect the flow of the game.

I think they are great, adds another dimension and tension while the electronic ref is being "consulted"

In cricket you only have so many times you can challenge the human ref with the camera ref, say for LBW.

The camera and software track the trajectory of the ball to see if it would have hit the stumps or not on the replay.

Not easy as swing spin and air density all have to be factored in as well as velocity and where the ball pitches.

 

[russ_watters]

In this case, it was first down by an inch.

One inch is tough, but not impossible precision with video. There was one a year or two ago where the ref slipped an index card between the ball and the pole to tell.

 

[russ_watters]

Football games (or any sport) are not decided by one play... they're decided by the entirety of the game.

Coaches say this a lot and while it seems true in hindsight and at a high level, IMO it isn't true in the progression of the game. The reason is that the strategy changes as the game progresses because the risk/reward calculus depends on the current score and time remaining to correct an old or new mistake. This is true to a great extent in most games/sports, but seems to be more true in American football than in most because of how easy it is for one big play to make a big difference in a close game. It also creates substantial opportunities for the team behind to come back and win, since the team ahead often adopts a very low risk/low reward strategy that backfires against the high risk/high reward strategy of the team behind.

That said, it is difficult to evaluate the game-altering ability of an early play due to how much of the game can be changed by one changed play.

It would waste far too much time to use instant replay on every single play, considering games already last so long. One bad call--- no matter how awful or momentum-changing--- will not decide a game.

It's only the close plays that need to be challenged, but as @sophiecentaur said, a move to electronic officiating would take care of both the accuracy and time issues.

 

[Comeback City]

@russ_watters
Obviously, plays towards the end of the game have a heavy influence on the outcome of a game. But how did they get to that close score at the end of the game? How did they get to that 4th down on the goal line with 3 seconds left? Why not just play a 5-minute game so every play is a big play? The "big plays" you speak of are only "big" because they're closer to the end, and thus get more attention from everyone invested. From playing and watching many sports, I can tell you that many games are decided right at the beginning. A few quick goals in a soccer game can set up for the possibility of a comeback at the end, but that comeback doesn't happen too often.

 

[sophiecentaur]

Sport is not Science and people behave irrationally. Worse still is the way that commentators describe games in terms of logic.
Then there’s “what a great goal that would have been”

 

[Chestermiller]

Guys,

My goal was purely scientific and was not focused either on the pros and cons of instant replays, officiating, or announcing a game. It was much more primordial than that. I wanted to find out if it would be possible to ruin the "win" for hated rival Ohio State fans by "proving" scientifically that the spot was bad and that they really "lost the game." This is part of the never-ending feud between Michigan and "Duh" Ohio State University.

Chet

 

[gmax137]

"Proving" the actual location of the ball at the end of the fourth down doesn't really help, unless you also "prove" that the ball was spotted correctly at the start of the play (that is, the third down spot wasn't incorrect). And so on, with the second and first downs. Maybe the entire series of downs was off by an inch either way.

 

[Chestermiller]

"Proving" the actual location of the ball at the end of the fourth down doesn't really help, unless you also "prove" that the ball was spotted correctly at the start of the play (that is, the third down spot wasn't incorrect). And so on, with the second and first downs. Maybe the entire series of downs was off by an inch either way.

You're talking mathematics and I'm talking hatred of Ohio State. Get the picture? I don't care if it is exactly mathematically correct as long as it ruins things for them.

 

[gmax137]

I don't care if it is exactly mathematically correct as long as it ruins things for them.

Got it!

 

[bucket]

Unfortunately, recent advances in sports broadcasting such as improved camera angles and high definition video have made it possible to very accurately measure the speed of a runner or thrown ball. You see this all the time as the announcers discuss how quickly a ball leaves the quarterbacks hand or how fast a running back cuts to avoid a tackle. As we all know by now, the more precise information we have about the balls velocity, the more uncertain we are forced to be about the balls position. So sadly, we will soon never be able to disprove any bad spots.

 

[jbriggs444]

My goal was purely scientific

I'm talking hatred of Ohio State

Pick one or the other.

 

[Chestermiller]

I'm still dissatisfied with the answers I've gotten to my question. So let me be a little more precise with my problem statement:

How would a team of scientists apply present-day technology to the existing video evidence, both official and unofficial (the latter from available cell phones and other video devices in the stands) to ascertain as closely as possible the 3D geometric location of the leading edge of the football at the moment that J.T. Barrett's knee (or other body part acceptable for establishing the end of the play) first touched the ground? What precision could be expected?

 

[Nik_2213]

UK Soccer introduced 'goal line technology' for the Premier League and some other competitions, but its coverage is 'goal mouth only'. However, when there's been a mid-field incident, eg leading to a yellow or red card and possible 'totting up' penalties such as multi-match bans, a player may appeal after the match based on multi-angle media footage. Of course, when ref says 'GO', the player had better go quietly...

Admittedly, there is a human element. Some soccer players have a reputation for being very, very easy to trip. Deliberately 'diving' when tackled is a serious offence, but hard to prove during the game. When one such player 'goes down' easily, perhaps too easily, the tackler is more likely than not to receive the benefit of the doubt...

 

[Chestermiller]

UK Soccer introduced 'goal line technology' for the Premier League and some other competitions, but its coverage is 'goal mouth only'. However, when there's been a mid-field incident, eg leading to a yellow or red card and possible 'totting up' penalties such as multi-match bans, a player may appeal after the match based on multi-angle media footage. Of course, when ref says 'GO', the player had better go quietly...

Admittedly, there is a human element. Some soccer players have a reputation for being very, very easy to trip. Deliberately 'diving' when tackled is a serious offence, but hard to prove during the game. When one such player 'goes down' easily, perhaps too easily, the tackler is more likely than not to receive the benefit of the doubt...

You do realize we are talking about American football here, not soccer, right?

 

[Comeback City]

You do realize we are talking about American football here, not soccer, right?

I think he was just giving another example, although American football definitely has more plays that could be considered worthy of video review.

Your question is tricky... officials are generally able to review placement calls in a matter of a couple minutes in games, but it sounds like you’re asking to find an exact coordinate position of the ball. Someone mentioned a tracking system in the ball and how that would make this a lot easier. But based solely on footage, it could take maybe an hour of video analysis of ALL videos available at that moment to determine placement with precision reasonable to what the human eye can distinguish. I could be wrong but that’s how I see this situation.

Maybe another UM person could give you a better answer... Go Terps!

 

[pbuk]

A tracker inside the ball won't help work out where the carrier's knee touched the ground.

And please change the title of the thread - American Football has no axioms and so it is not possible to prove anything about it mathematically.

 

[Comeback City]

A tracker inside the ball won't help work out where the carrier's knee touched the ground.

If the tracker is time-synced with the game clock then one could visually determine at what time the carrier's knee hit the ground and then use the tracker to determine the coordinate position at that time.

 

[Andy Resnick]

I'm still dissatisfied with the answers I've gotten to my question. So let me be a little more precise with my problem statement:

How would a team of scientists apply present-day technology to the existing video evidence, both official and unofficial (the latter from available cell phones and other video devices in the stands) to ascertain as closely as possible the 3D geometric location of the leading edge of the football at the moment that J.T. Barrett's knee (or other body part acceptable for establishing the end of the play) first touched the ground? What precision could be expected?

It doesn't matter- you lost :)

(sorry, couldn't resist)

 

[Noel]

You should be aware that the video systems that 'project' the line of scrimmage & first down target etc are all based on knowing exactly where a series of cameras are in relation to the field: angles to the corners, elevation, etc. That system is inherently accurate and precise enough to position the ball after each play, so long as a view of the ball at the end of the play is available.

 

[boneh3ad]

I always figured RFID sensors in the ball (tips, around the perimeter traced by the semiminor axis, etc.) plus sensors embedded in the field to track them would be able to do this pretty accurately. As mentioned before, syncing the position to the game clock would mean that instant replay would allow the precise location of the ball to be known at the point of any frame of video.

Of course, placing the sensors could be tricky, but it would be a fun thing to try.

Obligatory edit to support my own almae matres:
Go Illini!
Gig 'Em!
(But mostly Go Illini!)

 

[Chestermiller]

A tracker inside the ball won't help work out where the carrier's knee touched the ground.

And please change the title of the thread - American Football has no axioms and so it is not possible to prove anything about it mathematically.

Thanks for the unsolicited advice on terminology. Here's an axiom for you: it's a bad idea to try to make a PF moderator appear ignorant.

 

[boneh3ad]

And please change the title of the thread - American Football has no axioms and so it is not possible to prove anything about it mathematically.

I bet you're popular at parties.

 

[pbuk]

I bet you're popular at parties.

I wouldn't make that comment at a party. Or in the "General Discussion" forum here - but this is a Physics forum where technical questions are asked and technical answers given.

 

[boneh3ad]

I wouldn't make that comment at a party. Or in the "General Discussion" forum here - but this is a Physics forum where technical questions are asked and technical answers given.

Would you accept "use mathematics to reduce the uncertainty of a football spot to triviality" as an alternative proposal?

Give me a break. You can have an intelligent discussion without being a pedant.

 

[Greg Bernhardt]

Ok folks the tangent is over. Let's bring this back on topic or posts will start being removed.

 

[gmax137]

RFIDs, sensors, etc. etc. are no good here, because Chet wants to investigate the position of the ball at a certain time in a game that already took place in 2016. He is not interested in any other game. So the question is, do we have available data from the 2016 game to definitively prove the particular "spot" in question was bad?

 

[boneh3ad]

RFIDs, sensors, etc. etc. are no good here, because Chet wants to investigate the position of the ball at a certain time in a game that already took place in 2016. He is not interested in any other game. So the question is, do we have available data from the 2016 game to definitively prove the particular "spot" in question was bad?

I suppose I interpreted this as requesting tech that could prevent these kinds of issues in the future, but you may have a point.

I would imagine doing this a posteriori would be effectively impossible since the ball is often obscured from view. I suppose you may be able to look at how a runner is carrying a ball and run some numbers on how balls typically behave and create a confidence interval on where it is located, but even that seems iffy to me. It would be based on a lot of assumptions.

 

[Dr. Courtney]

Video analysis is straightforward with a well marked playing surface.

For me, the challenge would be more in the error analysis (what are the uncertainties in position for any given "spot") and in the definition of "bad spot."

Sports fans tend to focus on numbers without consideration of uncertainty. If the spot should have been at the 40 yard line, a foot short of the first down line to gain, most fans would argue it should not have been a first down, regardless of the uncertainty in the spot from the video analysis. Given sufficiently high frame rate, video resolution, and an unobstructed view of the player and ball as he hit the ground, it should usually be possible to reconstruct a video spot to much better than a foot. With original video of high profile NCAA games, video quality is rarely the issue - the challenge in accuracy is with an unobstructed view.

Defining a "bad spot" also requires attention. I would think a good approach would be to reconstruct all the spots from a large number of games in the Big 10 to get an accurate distribution of official spot accuracy. Then one defines a "bad spot" something like outside 2 standard deviations from the mean. or worse than 95% of spots in the Big 10. If the accuracy of a given spot is only worse than 50-75% of spots in the given conference, it may be unfortunate, but it really was not that bad.

 

[eachus]

There are two contributions to spotting the football. Let's assume we have a football with an IoT tag that can be placed accurately to within a fraction of an inch, and the officials not only have the necessary tools to place the ball, but the needed training with the tools so they can do it quickly.

Now we have just a few problems remaining. Where was the ball when the ball carrier stepped out of bounds? No way to get that right without instrumenting the sidelines. Might as well do the same for the out-of-bounds at each end of the field. That leads to the problem of documenting the position of the ball when a runner's knee touches. This is more of a timing issue, and we could put a device on the official's whistle. Might not be perfect but about as good as you can get. Much better than the current situation where the delay in hearing the whistle depends on the distance from the listener--electronic or otherwise.

Now, what about fouls away from the ball? When the penalty is measured from the point of infraction, the referee's judgement is back in the game. One fix would be to define the penalty from the position of the ball at the time of infraction--or the line of scrimmage when pass interference occurs as the ball is being thrown.

Have I covered all cases? Probably not. The NFL is smart enough that if they introduced such technology, they would limit its use to specific situations to begin with. Until then, the NFL and NCAA will have to rely on the integrity of the officials. Notice that the Michigan--Ohio State call was one of the few cases where the team could appeal to the league, and perhaps get the call, and game result changed. This is much more common, if still rare, in major league baseball, where the game can be replayed from the point of the error. Michigan not appealing--whether successful or not--leads me to guess that the official call was right, or if wrong not provably so from all the video evidence.

 

[boneh3ad]

Video analysis is straightforward with a well marked playing surface.

For me, the challenge would be more in the error analysis (what are the uncertainties in position for any given "spot") and in the definition of "bad spot."

Sports fans tend to focus on numbers without consideration of uncertainty. If the spot should have been at the 40 yard line, a foot short of the first down line to gain, most fans would argue it should not have been a first down, regardless of the uncertainty in the spot from the video analysis. Given sufficiently high frame rate, video resolution, and an unobstructed view of the player and ball as he hit the ground, it should usually be possible to reconstruct a video spot to much better than a foot. With original video of high profile NCAA games, video quality is rarely the issue - the challenge in accuracy is with an unobstructed view.

Defining a "bad spot" also requires attention. I would think a good approach would be to reconstruct all the spots from a large number of games in the Big 10 to get an accurate distribution of official spot accuracy. Then one defines a "bad spot" something like outside 2 standard deviations from the mean. or worse than 95% of spots in the Big 10. If the accuracy of a given spot is only worse than 50-75% of spots in the given conference, it may be unfortunate, but it really was not that bad.

I would like to see said data then broken down by referee to show us which ones are actually blind and which ones are just accused of such by fans.

 

[256bits]

There is also the forward progress rule, which is interpretive by the referee as to stoppage of play and placement of the ball.
No much a camera or any sensing unit can do here.

 

[Nik_2213]

Given my earlier comment about 'goal mouth technology', I was primed to notice a recent feature on the BBC TV's 'Click' IT program. This reported on commercial 'full 3-D' match recording, using dozens (40+) of 4K video cameras around the field plus 'cloud computing' to provide real-time, immersive, fly-through and play-back. In effect, it turned the event into VR, to be viewed / reviewed from any position, at any angle, at any speed.

I... I know just enough about algorithms & computational overheads of 3D modelling, CAD etc to be seriously impressed...

Okay, a surfeit of challenges would seriously slow most games, but a strict team limit should work. Also, a team may earn much kudos for challenging a marginal call that went in their favour...

 

[member 656954]

Obviously, plays towards the end of the game have a heavy influence on the outcome of a game.

Interestingly, 'Jeopardy!' contestant James Holzhauer adopts the exact opposite of this in his game play, and I head him on a NPR podcast say that coaches should go hard early because the risk is lower and the payoff higher. Early success places the team in a better position later in the game, yet, it seems that many games are played exactly opposite to this, leading to that heavy influence.

 

[Comeback City]

Interestingly, 'Jeopardy!' contestant James Holzhauer adopts the exact opposite of this in his game play, and I head him on a NPR podcast say that coaches should go hard early because the risk is lower and the payoff higher. Early success places the team in a better position later in the game, yet, it seems that many games are played exactly opposite to this, leading to that heavy influence.

That's what I was talking about in my first post (#3)... the entirety of the game is important, obviously.