5 ms·

Algorithms predict sports teams' moves with 80% accuracy [pdf]

68 points by mateja 4y ago

kayodelycaon 4y ago
Title is misleading. This is about classifying volleyball players and predicting their actions up to 2 seconds in advance. Which is really impressive. Humans do this automatically without even thinking about. General artificial intelligence is a still long way away, but the slow progress and exploration is fascinating to watch.
- throwawaylinux 4y ago
  I don't know if this is progress towards AGI. All life and all intelligence is just taking input and matching it against previous inputs and/or some hard-wiring as a way to make a decision. So in that sense you could say that any improvement in pattern recognition is (slow) progress toward AGI. I don't know if that is useful though, because I don't know if there is some progression from this to that. In other words, using such broad criteria means you could say that improvement to any pattern recognition or any algorithm that takes an input and decides something to create an output is progress toward AGI, but it's clearly not. So I'm not really sure if all this is any more than a souped-up "tree recognition neural network on a 16x16 pixel grid" that was the staple of "AI" neural net homework back in the 1980s, or even the old "expert system".
- spywaregorilla 4y ago
  I don't know volleyball well, but isn't it fairly deterministic within the window of 2 seconds? Like... your teammate just set the ball. What are you going to do? Isn't ALWAYS spike the ball?
  - bluGill 4y ago
    The ball is moving fast enough that for at least some moves the previous person hasn't yet touched the ball 2 seconds before, you cannot block a spike if you are not in the air before the spiker touches the ball. The spiker of course will be watching you and change how the ball is spiked based on that (if you don't make any attempt to block at all the spiker will drive the ball hard into the ground, if you do it is either find the hole in your defense to spike through, or tip the ball over the blocker making the return a lot easier) I only played at a college class level (I wasn't the best in my class, not a pro for sure) - yet I can do the above.
    - spywaregorilla 4y ago
      But then in this case the spiker is still spiking, the blocker is still jumping, no? There is no particular room for alternative states for competent players?
uptownfunk 4y ago
What will be the effects on betting once the outcomes from the models have been priced in. I suspect odds will get wildly out of balance.
- rybosome 4y ago
  I was wondering about that as well. Somebody is going to make a killing before they close the loophole, a modern day casino heist.
  - NavinF 4y ago
    The abstract talks about predicting 48 frames ahead. Is realtime sports betting even a thing? And if so is the liquidity and spread good enough to enter/exit say a $10,000 position that quickly?
    - csa 4y ago
      > Is realtime sports betting even a thing? Yes. It’s a growth area in sports betting. > And if so is the liquidity and spread good enough to enter/exit say a $10,000 position that quickly? In some sports, sure. Probably not in volleyball. The threat in the field is that some people have a slightly faster access to info than others (3-5 secs for live versus broadcast, iirc). If the result of an algo can push a betting line (e.g., predicting a tying point in a volleyball match), then automated bet placement software/script can make a prediction and get a bet in before the action is seen by bettors who are watching on broadcast. Even without prediction software, this is a very real problem with real time sports betting right now. It seems like functional prediction software can make this knowledge gap larger.
    - traceroute66 4y ago
      > Is realtime sports betting even a thing? And if so is the liquidity and spread good enough I think the question you really need to be asking is .... Is there a house that will let me do this ? The house tends not to like consistent winners.
glouwbug 4y ago
I bet it can predict that the Canucks will never win the playoffs either
thom 4y ago
It’d certainly be interesting to see if 80% accuracy over a 2 second window was enough to exploit tactically. If so, you’ve probably just saved a few hours of a video analyst’s time. Interesting approach though. There’s been a lot of work on this over the years, including on (dare I say) more complex sports like soccer. This was from Sloan 5 years ago for example: http://www.yisongyue.com/publications/ssac2017_ghosting.pdf http://www.yisongyue.com/publications/ssac2017_ghosting.pdf
- tanbog6 4y ago
  I'm pretty sure any skilled player can reliable judge what opposing players are going to in the next few seconds. Probably with closer to 95% accuracy.
  - littlestymaar 4y ago
    Especially for volleyball, because the only open question are: “to which attacker the setter will pass”, “where's the attacker going to attack” and “will the defense be able to get the ball”. For the “nine well-defined classes: spiking, blocking, set- ting, running, digging, standing, falling, waiting, and jumping” used in the paper, the only things that are hard to predict is “jumping”, for the attackers, because it depends on who the setter will pass the ball to, and who's going to be “falling” because it depends where the attacker will shoot the ball and which defender is in range to catch it. I've just tried to do it on a Youtube video, and it's actually a pretty fun game to play for a minute or two. (I think I'm above 85%, despite not having practiced volley outside of school's sport classes and never having watched it on TV, so I'm pretty convinced your 95% figure is well within reach of a skilled player).
  - thom 4y ago
    The interesting thing is whether you can identify exploitable tendencies in opposition team play (again, faster than your human analysts would otherwise do). If so, that takes preparation with the whole team rather than split second decision making.
krajzeg 4y ago
While impressive, volleyball is one of the most formulaic sports when it comes to predicting what happens next. This is not a dig on volleyball (I'm a fan!), but it is how the sport works. The first touch is always about receiving the ball and passing it cleanly to the setter. The second touch is about setting up the attacker (if possible). The third touch is a spike or other attempt to get the ball to the other side. The only significant decision points are usually who the setter chooses for the attack (among 2-4 players depending on formation), and on the defense side, where the blockers jump (3 players choosing spots to cover). Since the algorithm only predicts "actions", both of those don't matter (the setter is going to be "setting" regardless of who they choose, the blockers are always going to be "blocking" regardless of the spot they cover). The "team strategy" part is in effect just a check of whether the algorithm knows what is happening on the court at all. Volleyball allows the aforementioned three touches, and what the team is doing for each touch is pretty much immutable (the only source of variation is if one of the "steps" fails). This is of course still an achievement, but the choice of sport gives the researchers a leg up, since volleyball has significantly fewer "degrees of freedom" than other sports. In that context, ~80% accuracy at predicting an action 2 seconds out is less interesting, and it's unlikely that it's anywhere close to human performance for this particular sport.
- vander_elst 4y ago
  Thinking the same thing! Volleyball is very structured, there are schemas and tactics basically for every event in the game. Additionally, at professional level the accuracy of the players is quite high so the variability should get lower e.g. the setter will set the ball very precisely and the spiker will attack from a specific position. What it might change is the timing (depending on how high the ball is), but usually the professional games are very fast so that should also simplify things.
- fatnoah 4y ago
  > This is not a dig on volleyball I see what you did there!
halflings 4y ago
The paper doesn't mention any baseline, and so claims like "86% accuracy" are a bit useless: what if players do the same action 85% of the time? Then the model wouldn't be not predicting much. If on the other hand the most common action happens only 30% of the time, then that would be an incredibly strong result.
- littlestymaar 4y ago
  I wonder what accuracy you'd get in a basketball game with the following constant predictor: “the player who has the ball will dribble”.
- bluGill 4y ago
  Bump-set-spike. That is how all great players play. There are exceptions for things like they messed up; or are exploiting surprise to do something wrong hoping it works out. At amateur level it is much harder to predict as nobody follow thee proper order, and in turn this makes it really easy for someone just a little better than average win.
jugg1es 4y ago
I'd like to see an attempt to predict the movement of an NFL defense based on the starting positions of both the offense and defense. Seems like a much harder problem than volleyball, yet is something that human experts can clearly do on the fly.
- kenjackson 4y ago
  Humans struggle with it too. I would be interested in the study you suggest. NFL defense work hard to mask their schemes.

68 points by mateja 4y ago

Title is misleading. This is about classifying volleyball players and predicting their actions up to 2 seconds in advance. Which is really impressive. Humans do this automatically without even thinking about. General artificial intelligence is a still long way away, but the slow progress and exploration is fascinating to watch.

throwawaylinux 4y ago
I don't know if this is progress towards AGI. All life and all intelligence is just taking input and matching it against previous inputs and/or some hard-wiring as a way to make a decision. So in that sense you could say that any improvement in pattern recognition is (slow) progress toward AGI. I don't know if that is useful though, because I don't know if there is some progression from this to that. In other words, using such broad criteria means you could say that improvement to any pattern recognition or any algorithm that takes an input and decides something to create an output is progress toward AGI, but it's clearly not. So I'm not really sure if all this is any more than a souped-up "tree recognition neural network on a 16x16 pixel grid" that was the staple of "AI" neural net homework back in the 1980s, or even the old "expert system".
spywaregorilla 4y ago
I don't know volleyball well, but isn't it fairly deterministic within the window of 2 seconds? Like... your teammate just set the ball. What are you going to do? Isn't ALWAYS spike the ball?
- bluGill 4y ago
  The ball is moving fast enough that for at least some moves the previous person hasn't yet touched the ball 2 seconds before, you cannot block a spike if you are not in the air before the spiker touches the ball. The spiker of course will be watching you and change how the ball is spiked based on that (if you don't make any attempt to block at all the spiker will drive the ball hard into the ground, if you do it is either find the hole in your defense to spike through, or tip the ball over the blocker making the return a lot easier) I only played at a college class level (I wasn't the best in my class, not a pro for sure) - yet I can do the above.
  - spywaregorilla 4y ago
    But then in this case the spiker is still spiking, the blocker is still jumping, no? There is no particular room for alternative states for competent players?

uptownfunk 4y ago

What will be the effects on betting once the outcomes from the models have been priced in. I suspect odds will get wildly out of balance.

rybosome 4y ago
I was wondering about that as well. Somebody is going to make a killing before they close the loophole, a modern day casino heist.
- NavinF 4y ago
  The abstract talks about predicting 48 frames ahead. Is realtime sports betting even a thing? And if so is the liquidity and spread good enough to enter/exit say a $10,000 position that quickly?
  - csa 4y ago
    > Is realtime sports betting even a thing? Yes. It’s a growth area in sports betting. > And if so is the liquidity and spread good enough to enter/exit say a $10,000 position that quickly? In some sports, sure. Probably not in volleyball. The threat in the field is that some people have a slightly faster access to info than others (3-5 secs for live versus broadcast, iirc). If the result of an algo can push a betting line (e.g., predicting a tying point in a volleyball match), then automated bet placement software/script can make a prediction and get a bet in before the action is seen by bettors who are watching on broadcast. Even without prediction software, this is a very real problem with real time sports betting right now. It seems like functional prediction software can make this knowledge gap larger.
  - traceroute66 4y ago
    > Is realtime sports betting even a thing? And if so is the liquidity and spread good enough I think the question you really need to be asking is .... Is there a house that will let me do this ? The house tends not to like consistent winners.

glouwbug 4y ago

I bet it can predict that the Canucks will never win the playoffs either

thom 4y ago

It’d certainly be interesting to see if 80% accuracy over a 2 second window was enough to exploit tactically. If so, you’ve probably just saved a few hours of a video analyst’s time. Interesting approach though. There’s been a lot of work on this over the years, including on (dare I say) more complex sports like soccer. This was from Sloan 5 years ago for example: http://www.yisongyue.com/publications/ssac2017_ghosting.pdf http://www.yisongyue.com/publications/ssac2017_ghosting.pdf

tanbog6 4y ago
I'm pretty sure any skilled player can reliable judge what opposing players are going to in the next few seconds. Probably with closer to 95% accuracy.
- littlestymaar 4y ago
  Especially for volleyball, because the only open question are: “to which attacker the setter will pass”, “where's the attacker going to attack” and “will the defense be able to get the ball”. For the “nine well-defined classes: spiking, blocking, set- ting, running, digging, standing, falling, waiting, and jumping” used in the paper, the only things that are hard to predict is “jumping”, for the attackers, because it depends on who the setter will pass the ball to, and who's going to be “falling” because it depends where the attacker will shoot the ball and which defender is in range to catch it. I've just tried to do it on a Youtube video, and it's actually a pretty fun game to play for a minute or two. (I think I'm above 85%, despite not having practiced volley outside of school's sport classes and never having watched it on TV, so I'm pretty convinced your 95% figure is well within reach of a skilled player).
- thom 4y ago
  The interesting thing is whether you can identify exploitable tendencies in opposition team play (again, faster than your human analysts would otherwise do). If so, that takes preparation with the whole team rather than split second decision making.

krajzeg 4y ago

While impressive, volleyball is one of the most formulaic sports when it comes to predicting what happens next. This is not a dig on volleyball (I'm a fan!), but it is how the sport works. The first touch is always about receiving the ball and passing it cleanly to the setter. The second touch is about setting up the attacker (if possible). The third touch is a spike or other attempt to get the ball to the other side. The only significant decision points are usually who the setter chooses for the attack (among 2-4 players depending on formation), and on the defense side, where the blockers jump (3 players choosing spots to cover). Since the algorithm only predicts "actions", both of those don't matter (the setter is going to be "setting" regardless of who they choose, the blockers are always going to be "blocking" regardless of the spot they cover). The "team strategy" part is in effect just a check of whether the algorithm knows what is happening on the court at all. Volleyball allows the aforementioned three touches, and what the team is doing for each touch is pretty much immutable (the only source of variation is if one of the "steps" fails). This is of course still an achievement, but the choice of sport gives the researchers a leg up, since volleyball has significantly fewer "degrees of freedom" than other sports. In that context, ~80% accuracy at predicting an action 2 seconds out is less interesting, and it's unlikely that it's anywhere close to human performance for this particular sport.

vander_elst 4y ago
Thinking the same thing! Volleyball is very structured, there are schemas and tactics basically for every event in the game. Additionally, at professional level the accuracy of the players is quite high so the variability should get lower e.g. the setter will set the ball very precisely and the spiker will attack from a specific position. What it might change is the timing (depending on how high the ball is), but usually the professional games are very fast so that should also simplify things.
fatnoah 4y ago
> This is not a dig on volleyball I see what you did there!

halflings 4y ago

The paper doesn't mention any baseline, and so claims like "86% accuracy" are a bit useless: what if players do the same action 85% of the time? Then the model wouldn't be not predicting much. If on the other hand the most common action happens only 30% of the time, then that would be an incredibly strong result.

littlestymaar 4y ago
I wonder what accuracy you'd get in a basketball game with the following constant predictor: “the player who has the ball will dribble”.
bluGill 4y ago
Bump-set-spike. That is how all great players play. There are exceptions for things like they messed up; or are exploiting surprise to do something wrong hoping it works out. At amateur level it is much harder to predict as nobody follow thee proper order, and in turn this makes it really easy for someone just a little better than average win.

jugg1es 4y ago

I'd like to see an attempt to predict the movement of an NFL defense based on the starting positions of both the offense and defense. Seems like a much harder problem than volleyball, yet is something that human experts can clearly do on the fly.

kenjackson 4y ago
Humans struggle with it too. I would be interested in the study you suggest. NFL defense work hard to mask their schemes.