So, there is a debate over at Knickerblogger going on about exactly how stupid J.R. Smith's three point heave was last night. J.R. didn't realize the game was tied and took a wide open three after the Knicks had grabbed an offensive rebound with less than 24 second remaining.
A poster named PTMilo thinks that the Knicks might actually have been better off with JR taking that shot, if you give him a bump for having a wide open in rhythm opportunity
http://knickerblogger.net/knicks-mornin ... ent-457441
Relevant comments start at #5
I was curious, anyone care to take a crack at estimating the various probabilities, like the basketballs stat-savants you are? To me, given the applicable circumstances, holding for the last shot seems like the dominant strategy, quite obviously. But I was curious what a sophisticated basketball mind makes of the equity gain or loss from JR's heave.
Who Shot? JR - Stupid but how stupid, really?
Re: Who Shot? JR - Stupid but how stupid, really?
This is what I posted from the other thread on Wins Probability calculator where I had also brought this up:
Thanks.
Supposing there was a 40% chance of that 3-pointer going in (it was a wide open look off an offensive rebound), and a 30% chance they get the offensive rebound in case of a miss. There's an 88.2% of them winning if the 3-pointer is good, and a 45.6% chance of them winning if its no good (the latter is probably a bit high, since its not factoring that the Knicks were the road team). So, this comes to a 62.6% chance of the Knicks winning the JR shooting the shot. On the other hand, the calculator gives the Knicks a 60.8% chance of winning when they have the ball with 19 seconds left and the game tied (again, probability a bit high since the Knicks are the road team).
If instead we give JR a 34% chance of making it (his season average), then the probability of the Knicks winning with him taking the shot drops down to 60.1%.
From this, it seems like it was a close call and Smith was unfairly blasted for it.
-
talkingpractice
- Posts: 194
- Joined: Tue Oct 30, 2012 6:58 pm
- Location: The Alpha Quadrant
- Contact:
Re: Who Shot? JR - Stupid but how stupid, really?
There are a number of assumptions in the hickory-high piece that are at least debatable. What better forum than this to debate them? I don't know necessarily that the assumptions are incorrect, but I would like to raise some concerns or propose alternatives. I think I can at least show that the final win percentages are sensitive to these initial assumptions.
1. The assumption that J.R. Smith is 44% on that shot.
Smith was 1-8 on 3s in the game, 1-7 leading up to that shot. He's shooting 34.1% from behind the arc this season. They note that Smith is shooting 42.2% off ORB (on 3-pointers) since the beginning of last season. If I'm reading my query on nbawowy correctly, Smith is only 3-10 this season in such scenarios.
2. The Knicks have a .3 chance of winning in overtime.
Yes, the Knicks are away, and Houston was supposed to win, but with 19 seconds to go, the Knicks had the ball in a win or OT situation. Why would we assume that overtime would be so different than the first 47 minutes of the game?
3. If Smith doesn't shoot, the Knicks have a .35% chance of winning in regulation.
This is based on the assumption that Anthony would get one last shot and that he would shoot 35% in that situation. Honestly, I don't know that I would give Anthony more than 35% on the final shot (but if we're giving Smith 44% on his 3?). What I find interesting here is that although a high ORB% is assigned to Smith's shot, there is no consideration for Chandler getting a put back or tap in on Anthony's shot. Perhaps Carmelo would fire as the buzzer sounds, but should we assume this?
4. Houston has a 35% chance of winning in regulation if Smith misses.
This is based on Harden having a 35% chance of scoring. I guess at this point I should point out that we're assuming Smith to shoot a significantly higher percentage than his season average in his shot, but both Harden and Anthony to shoot significantly less than their respective percentages in ISOs this season (both over 40%). It's not the 35% that bothers me here though. It's the assumption that if Smith misses, Houston will go to Harden in an isolation. We aren't accounting for other possibilities. In fact, what actually happened was a foul on Brooks. So, we can be certain that other routes to a Houston win are possible. Should we give Houston a chance for an ORB on Harden's miss?
The article reports a 54% chance of NY winning on Smith's shot and a 55% chance of them winning on NY holding for the last shot. If you don't believe at least one of these assumptions, you'll arrive at a significantly different conclusion. If you take all of the other assumptions and give Smith (1-7 on 3P for the night before the shot) 34% on his shot (his season average), the Knicks chance of winning drops to 48% if Smith shoots. Assuming Smith shoots 34% on that shot, NY has a 40% chance of winning in regulation if they hold, and NY has a 45% chance of winning in overtime, you get a 67% vs. 55% split on hold vs. bonehead shot.
1. The assumption that J.R. Smith is 44% on that shot.
Smith was 1-8 on 3s in the game, 1-7 leading up to that shot. He's shooting 34.1% from behind the arc this season. They note that Smith is shooting 42.2% off ORB (on 3-pointers) since the beginning of last season. If I'm reading my query on nbawowy correctly, Smith is only 3-10 this season in such scenarios.
2. The Knicks have a .3 chance of winning in overtime.
Yes, the Knicks are away, and Houston was supposed to win, but with 19 seconds to go, the Knicks had the ball in a win or OT situation. Why would we assume that overtime would be so different than the first 47 minutes of the game?
3. If Smith doesn't shoot, the Knicks have a .35% chance of winning in regulation.
This is based on the assumption that Anthony would get one last shot and that he would shoot 35% in that situation. Honestly, I don't know that I would give Anthony more than 35% on the final shot (but if we're giving Smith 44% on his 3?). What I find interesting here is that although a high ORB% is assigned to Smith's shot, there is no consideration for Chandler getting a put back or tap in on Anthony's shot. Perhaps Carmelo would fire as the buzzer sounds, but should we assume this?
4. Houston has a 35% chance of winning in regulation if Smith misses.
This is based on Harden having a 35% chance of scoring. I guess at this point I should point out that we're assuming Smith to shoot a significantly higher percentage than his season average in his shot, but both Harden and Anthony to shoot significantly less than their respective percentages in ISOs this season (both over 40%). It's not the 35% that bothers me here though. It's the assumption that if Smith misses, Houston will go to Harden in an isolation. We aren't accounting for other possibilities. In fact, what actually happened was a foul on Brooks. So, we can be certain that other routes to a Houston win are possible. Should we give Houston a chance for an ORB on Harden's miss?
The article reports a 54% chance of NY winning on Smith's shot and a 55% chance of them winning on NY holding for the last shot. If you don't believe at least one of these assumptions, you'll arrive at a significantly different conclusion. If you take all of the other assumptions and give Smith (1-7 on 3P for the night before the shot) 34% on his shot (his season average), the Knicks chance of winning drops to 48% if Smith shoots. Assuming Smith shoots 34% on that shot, NY has a 40% chance of winning in regulation if they hold, and NY has a 45% chance of winning in overtime, you get a 67% vs. 55% split on hold vs. bonehead shot.
-
Bobbofitos
- Posts: 306
- Joined: Sat Apr 16, 2011 7:40 am
- Location: Cambridge, MA
- Contact:
Re: Who Shot? JR - Stupid but how stupid, really?
It was a bad shot but probably not as atrocious as everyone (including me) thought when it was hoisted at the time.
http://pointsperpossession.com/
@PPPBasketball
@PPPBasketball
-
Jacob Frankel
- Posts: 35
- Joined: Mon Apr 08, 2013 6:45 am
Re: Who Shot? JR - Stupid but how stupid, really?
Steve, a couple rebuttals
1. You point out that JR was 1-7 in this game. Do you have statistical evidence that this is relevant? And 10 shots is minuscule sample size to judge how he's shooting in a specific situation. And again, the factor of being wiiiiiide open matters a lot.
2. Because of the study from boooooeeee I shared. All the games in that study went to overtime, but the team favored by 10 still won 68% of the time.
3 and 4. Smith shoots significantly higher than average because he's wide open. Melo and Harden shoot a lot lower because of the entire defense's focus and the nature of the situation. The numbers entirely back this up. If anything, I overvalued Melo and Harden's chances of scoring. The win prob calculator gives a team a 60% chance of winning with 19 seconds, the game tied, and the ball. And that assumes basically even odds in overtime. The tip-in/loose ball foul points are very valid ones, but I couldn't find numbers on these things and I think their impact would be pretty minor.
1. You point out that JR was 1-7 in this game. Do you have statistical evidence that this is relevant? And 10 shots is minuscule sample size to judge how he's shooting in a specific situation. And again, the factor of being wiiiiiide open matters a lot.
2. Because of the study from boooooeeee I shared. All the games in that study went to overtime, but the team favored by 10 still won 68% of the time.
3 and 4. Smith shoots significantly higher than average because he's wide open. Melo and Harden shoot a lot lower because of the entire defense's focus and the nature of the situation. The numbers entirely back this up. If anything, I overvalued Melo and Harden's chances of scoring. The win prob calculator gives a team a 60% chance of winning with 19 seconds, the game tied, and the ball. And that assumes basically even odds in overtime. The tip-in/loose ball foul points are very valid ones, but I couldn't find numbers on these things and I think their impact would be pretty minor.
Re: Who Shot? JR - Stupid but how stupid, really?
Jacob,
1. The hot hand in basketball is difficult to pin down. Evidence of the hot hand's existence in other sports is piling up, and we're beginning to realize the flaws in some of the tests previously used to try and assess the hot hand in basketball. I like this article on the topic
http://onlinelibrary.wiley.com/doi/10.1 ... 2/abstract
It appears to now be behind a paywall, but if you're interested, you could probably get a free preprint from the authors. I actually published a response to that article in the same journal (http://onlinelibrary.wiley.com/doi/10.1 ... 9/abstract), and I'd be happy send you a copy. Unfortunately, my article is more a case to reopen the case of the hot hand by establishing nonstationarity in 3-point competitions (and the home-run derby) where players shoot comparable shots in repetition without defense. Gaps in time between shots, defensive adjustments, and the varying difficulty of consecutive shots in basketball may be enough to eliminate any sort of hot hand phenomenon in actual gameplay, or it may be enough to hide it's effects from our statistical tests.
On JR's shot % here, I just think this is an example where you could make a compelling case in either direction. There seems to be as much evidence to suppose he's about 30% as there is to push to 44%. This is important because our evaluation of JR's decision heavily hinges on whether or not we believe NY can get a comparable shot (in terms of make %) with 3 seconds on the clock.
2. The overtime win% isn't as critical for the evaluation of JR's shot since there is a probability of going to OT in both the shoot and hold cases.
3. I am with you on the percentages of makes for Harden and Anthony here. I don't know that I would give either more than 35% on a final shot. My point was that the 44% on Smith with a 23% chance of ORB compared to a 35% on Anthony with a 0% chance of ORB might be as far in one direction as you could go with the assumptions.
The more I look at this, the more I like it as a problem for my spring quantitative analysis in sports class. I think I could produce a seemingly compelling statistical argument that it wasn't a terrible decision by Smith (maybe 3% swing in probabilities), and that it was a bonehead move (10-15% swing in probabilities). I'll let the students pick sides, run the numbers and debate. With a number of articles popping up claiming approximately equal win probabilities on shoot vs hold by presenting maybe one end of the spectrum of possible underlying assumptions, I felt the need to present the other perspective.
1. The hot hand in basketball is difficult to pin down. Evidence of the hot hand's existence in other sports is piling up, and we're beginning to realize the flaws in some of the tests previously used to try and assess the hot hand in basketball. I like this article on the topic
http://onlinelibrary.wiley.com/doi/10.1 ... 2/abstract
It appears to now be behind a paywall, but if you're interested, you could probably get a free preprint from the authors. I actually published a response to that article in the same journal (http://onlinelibrary.wiley.com/doi/10.1 ... 9/abstract), and I'd be happy send you a copy. Unfortunately, my article is more a case to reopen the case of the hot hand by establishing nonstationarity in 3-point competitions (and the home-run derby) where players shoot comparable shots in repetition without defense. Gaps in time between shots, defensive adjustments, and the varying difficulty of consecutive shots in basketball may be enough to eliminate any sort of hot hand phenomenon in actual gameplay, or it may be enough to hide it's effects from our statistical tests.
On JR's shot % here, I just think this is an example where you could make a compelling case in either direction. There seems to be as much evidence to suppose he's about 30% as there is to push to 44%. This is important because our evaluation of JR's decision heavily hinges on whether or not we believe NY can get a comparable shot (in terms of make %) with 3 seconds on the clock.
2. The overtime win% isn't as critical for the evaluation of JR's shot since there is a probability of going to OT in both the shoot and hold cases.
3. I am with you on the percentages of makes for Harden and Anthony here. I don't know that I would give either more than 35% on a final shot. My point was that the 44% on Smith with a 23% chance of ORB compared to a 35% on Anthony with a 0% chance of ORB might be as far in one direction as you could go with the assumptions.
The more I look at this, the more I like it as a problem for my spring quantitative analysis in sports class. I think I could produce a seemingly compelling statistical argument that it wasn't a terrible decision by Smith (maybe 3% swing in probabilities), and that it was a bonehead move (10-15% swing in probabilities). I'll let the students pick sides, run the numbers and debate. With a number of articles popping up claiming approximately equal win probabilities on shoot vs hold by presenting maybe one end of the spectrum of possible underlying assumptions, I felt the need to present the other perspective.
Re: Who Shot? JR - Stupid but how stupid, really?
The hot hand absolutely exists. I hate small sample sizes and inverted causal relationships and I still can see that the hot hand exists...though I do not believe it is in the way we think.
Let's face it, if the hot(or cold) hand exists then it's in the mind, and that to me suggests it will exist most for those players whose emotional attachment to their shooting stats is high. Personally I'm not sure Bargs, JR and Melo would register much on the shooting conscience scale.
Let's face it, if the hot(or cold) hand exists then it's in the mind, and that to me suggests it will exist most for those players whose emotional attachment to their shooting stats is high. Personally I'm not sure Bargs, JR and Melo would register much on the shooting conscience scale.
Re: Who Shot? JR - Stupid but how stupid, really?
Shooters got to shoot.
Re: Who Shot? JR - Stupid but how stupid, really?
Is it fair to say that if a virtual army of nerds with computers, taking several days, call this a toss-up decision, that for JR Smith, in a split-second, to decide to shoot is not stupid?
Really, it was only "bad" in that the shot missed. If he makes it, is he a genius?
Really, it was only "bad" in that the shot missed. If he makes it, is he a genius?
Re: Who Shot? JR - Stupid but how stupid, really?
Haha. I have many of times seen a coach on the verge of chastising a player for taking a bad shot only to bite their tongue when the shot went in.Mike G wrote:Is it fair to say that if a virtual army of nerds with computers, taking several days, call this a toss-up decision, that for JR Smith, in a split-second, to decide to shoot is not stupid?
Really, it was only "bad" in that the shot missed. If he makes it, is he a genius?
If NY was up by 1 or 2 at the time, and Smith takes the shot, it still would have been a split second decision, but maybe more clearly a bad one.
Re: Who Shot? JR - Stupid but how stupid, really?
Great thread! Thanks for the insights....
Re: Who Shot? JR - Stupid but how stupid, really?
While stat geeks crunch the numbers on whether or not JR Smith is a bonehead, JR himself decided to settle the matter once and for all:
http://espn.go.com/new-york/nba/story/_ ... ke-conduct
Smith was fined 50k for untying and attempting to untie opponents' shoelaces. Check out the video at
http://nba.si.com/2014/01/05/j-r-smith- ... cks-video/
I haven't calculated the win probabilities yet, but I'm fairly certain Smith would have been better off tying Marion's shoes together.
http://espn.go.com/new-york/nba/story/_ ... ke-conduct
Smith was fined 50k for untying and attempting to untie opponents' shoelaces. Check out the video at
http://nba.si.com/2014/01/05/j-r-smith- ... cks-video/
I haven't calculated the win probabilities yet, but I'm fairly certain Smith would have been better off tying Marion's shoes together.
-
talkingpractice
- Posts: 194
- Joined: Tue Oct 30, 2012 6:58 pm
- Location: The Alpha Quadrant
- Contact:
Re: Who Shot? JR - Stupid but how stupid, really?
Mike G wrote:Is it fair to say that if a virtual army of nerds with computers, taking several days, call this a toss-up decision, that for JR Smith, in a split-second, to decide to shoot is not stupid?
I think this summarizes my final feelings on the matter, fwiw.steveshea wrote:I haven't calculated the win probabilities yet, but I'm fairly certain Smith would have been better off tying Marion's shoes together.
Re: Who Shot? JR - Stupid but how stupid, really?
In general this is correct. However, specifically for JR Smith, it's a bit vague. First, here's some background that quantifies what you are talking about here: http://blog.cacvantage.com/2013/02/How- ... fense.htmlJacob Frankel wrote:Steve, a couple rebuttals
1. You point out that JR was 1-7 in this game. Do you have statistical evidence that this is relevant? And 10 shots is minuscule sample size to judge how he's shooting in a specific situation. And again, the factor of being wiiiiiide open matters a lot.
2. Because of the study from boooooeeee I shared. All the games in that study went to overtime, but the team favored by 10 still won 68% of the time.
3 and 4. Smith shoots significantly higher than average because he's wide open. Melo and Harden shoot a lot lower because of the entire defense's focus and the nature of the situation. The numbers entirely back this up. If anything, I overvalued Melo and Harden's chances of scoring. The win prob calculator gives a team a 60% chance of winning with 19 seconds, the game tied, and the ball. And that assumes basically even odds in overtime. The tip-in/loose ball foul points are very valid ones, but I couldn't find numbers on these things and I think their impact would be pretty minor.
Having looked at the shot, I think it would fall under the open category Vantage tracks (no player within 5 feet) although I'm not 100% sure. The research I've done shows the difference to be the following for above the break 3 point shots:
contested/pressured 3s- 32.0%
guarded 3s- 35.8%
open 3s- 39.9%
This aligns with the article I mentioned earlier. The article also mentions that the average is about 40% on open catch and shoot shots from above the break. Now in regards to the shot clock, JR took the shot in the first 5 seconds of the shot clock so using that split, we find open/guarded shots taken in the first 5 seconds of the shot clock from above the break go in at 39%.
So thats the background on the league. But for JR specifically? The difference was about 4% for contested/pressured shots versus open shots on 3s (38% vs. 42.2%). Parsing it down to only above the break 3s leads to a very small sample (19 fga's), so I think it makes sense to look at the overall difference on 3s for JR. In the general rule, contesting shots leads to a significant drop in FG%. But a good question would be: do some players have that ability where it doesn't matter if they are open or not? Additionally, the 3 point shot does have some whacky splits in that there isn't any difference between a contested shot (getting hand up) vs. pressured shot (no hand up).
In regards to Smith, he seems to be one of those players where the difference on contested vs. open shots for 3s is smaller.