November 21, 2009

An Open Letter to Bill Simmons

Filed under: Uncategorized — wwinston @ 9:48 am

Dear Bill:

            I am one of your millions of fans. I love your columns and podcasts. You inform  and entertain me several times a week.  We share a passionate love affair with Friday Night Lights and Mad Men. I was amazed when our school PR manager Lura Forcum informed me that you had mentioned me in your column. Since you do not seem to think much of my basketball statistical analysis I thought I should write a response to your column. So here goes.

Should Belichick have gone for the first down?

                You clearly think this was a bad decision. I think the decision is not clear cut, but math can shed a lot of light on this controversy. You quote several people on advanced topics like WIN PROBABILITY. Actually, things are not that complex. I think you agree with me that the decision depends on your estimate of three numbers.

MAKE = Chance Pats make first down

LONG = Chance Colts score TD after a punt.

SHORT = Chance Colts score TD after a failed first down attempt.

Intelligent people can differ in their estimates of these parameters. Whatever your parameter estimates, however, the math makes it pretty clear that the correct decision is to go for it if and only if


See my post on this earlier this week. I estimate MAKE = .5, LONG = .5 and SHORT =.8 so the formula says to go for it. I polled 10 college professors on this issue and based on their estimates going for it was the right decision for 70% of the professors.

            You point out that less than 40% of two point conversions attempted with passes were successful, so you clearly think that MAKE<.50. I would argue, however, that the short field makes it easy to defend a pass on a two point conversion, so this is not a relevant data point. During the last three years, teams have converted 4th and 2 passing attempts more than 55% of the time. Clearly the Pats have a great passing game, so I think a MAKE = .50 is reasonable, but people can differ on this. Clearly, however,  Belichick’s decision to go for it was not as crazy or irrational as many people think.

            Next you point out that only around one time a year does a team score 3 TD’s in the 4th quarter and win a game. This statistic has no relevance to the question at hand. What is relevant is the chance that a team which trailed by 18-20 points in the 4th quarter that has scored 2 TD’s in a row will score a TD if they get the ball with 2 minutes left. I bet there isn’t much data on that so you have to go with your gut feel here.

            In summary, reasonable people can come down either way on the question of whether the Pats should have gone for it.

            Let’s move on to basketball. Love your book by the way. Its status as the #1 best seller is well deserved.  I totally agree with you that stats are much more useful in baseball than basketball. This is because baseball is mostly a two man game between the pitcher and hitter (fielding does matter, but it now can be well measured).  I also agree with your comments in the book that Box Score metrics like PER miss a lot of the game. I love your discussion of why we need a stat that shows that Wes Unseld was a great player(“he made his teammates better in so many ways”). While over short spans of time Adjusted +/- has a lot of noise in it, over a large sample, Adjusted +/- gets at how a player adds (or subtracts) to a team’s success.  Essentially Adjusted +/- looks at every minute of every game and uses how the score moves, together with the 10 players on the court, to tease out the influence of each player on the score of the game So now let’s look at the two assertions you made on your blog:

·        Anyone who thinks KD was a below average NBA player must be pretty stupid.

·        Anybody who thinks Tim Thomas is underrated must be pretty stupid.

As Edwards Demings, the great American statistician used to say “In God we trust, all others need data.” So let’s look at your two assertions.

How did Kevin Durant perform during his First Two Seasons?

                KD had a PER of 24 last year, which indicates to box score followers that he was a great player. I do not think this was the case. His Adjusted +/- was -7 points for his first two seasons (other people get just about the same number). This indicates that after we adjust for who KD played with and against; our best estimate is that he reduced the Thunder’s performance by 7 points a game. After factoring in the noise, there is less than a 5% chance that KD’s Adjusted +/- for his first two seasons exceeded 0 (an average NBA player).  By the way ask your good friend Daryl Morey if he thinks it is “nonsense” to say KD hurt the Thunder during his first two seasons. To substantiate the fact that KD hurt rather than helped the team during his first two years look at the following numbers (standard deviation measures the “noise”).

Let’s break down all Thunder minutes during 2008-2009 into 3 lineup combinations and look at how (adjusting for strength of opposition) the Thunder played. The standard deviation of these estimates (rounded off) is also given

·                   Collison Westbrook Green and KD in +.4 points (std dev 4 points)

·                   All other KD minutes -11.2  points (st dev 2 points)

·                   All minutes with KD out -2.6 points (std dev 3 points

I hope you can enlighten me on how these numbers show that KD helped the Thunder win a lot of games.

   By the way right before KD was injured last year the Thunder was on a 7 game losing streak. As soon as he got hurt they went 5-2. I am sure you think that was a coincidence.

            Now the good news is that KD (and the Thunder) are playing great this year. Our numbers indicate that KD is an all star caliber player this year. Could this be because Henry Abbott in his gutsy  TRUE HOOP column pointed out KD’s shortcomings (failing to play the pick and roll correctly and shooting when doubled and tripled teamed)? Maybe KD corrected these flaws in his game and this led to his improvement. If you can ask KD if this is the case, I think it might make a great story. By the way to improve a team’s performance by 20 points a game, you need only score one more basket or give up one less basket on around one out of 20 possessions (assuming 200 possessions per game).

            On to Tim Thomas. Both you and Kevin Pelton (his Basketball Prospectus is also a great book) have written that Tim Thomas “defines a replacement (read bad) player.” I do not dispute your comments that Thomas did not hustle in many Clipper games. He may be a bad off court influence; I just do not know. But in over 20,000 minutes of NBA play his adjusted +/- rating is +0.78, so he grades out over his career as a slightly above average NBA player.  This is an awful lot of data. Basically, for all of Tim Thomas’ minutes we know who he played with and against and how the score of the game changed during each of his minutes on the court. Given this data, there is virtually no chance that Tim Thomas is as bad as you say he is (against ask Daryl Morey his opinion on this). Of course, if he hustled more he would have been better.  One final stat on Tim Thomas’ performance with the Knicks last year:

In 105 minutes with Gallinari, Harrington and Thomas in the Knicks played 22 points better than an average NBA team. In 140 minutes with Gallinari and Harrington in and Thomas out the Knicks only played 3 points better than average.

I think it should clear to a basketball expert like yourself that Tim Thomas let’s you spread the floor (he also did this with the Suns) and when he is on the court with guys who can shoot and drive he can make a team awfully hard to defend. This data certainly flies in the face of your assertion that Tim Thomas is worthless.

            Well, thanks for reading this. I emailed you last year when you dissed our rating of Jason Kidd. I wanted to show you why we had him rated as a good player, but I can appreciate how busy you are. Hope to hear from you sometime ( or 812-322-4270).

Sincerely yours,

Wayne Winston



  1. Whats your take for Lamar Odom this year? Seems like his plus minus numbers are way down when hes A) starting instead of coming of the bench and B) playing without Pau Gasol.

    Comment by Ryan — November 23, 2009 @ 1:56 pm

  2. He is not doing near as well. Maybe with Pau back he will do better. Kobe and Artest have been everything for them this year.

    Comment by wwinston — November 23, 2009 @ 2:10 pm

  3. You’re seriously arguing statistics and math with a guy who believes the dealer has an effect on his black jack results?

    Comment by Jeremy — November 23, 2009 @ 2:26 pm

  4. It would be interesting if you would take a bigger look into that once Pau Gasol plays more games with the team, It would be cool to see if there are large differences in adjusted +/- for Odom when he starts or comes off the bench and/or shares the front court with either Bynum or Gasol.

    Comment by Ryan — November 23, 2009 @ 2:31 pm

  5. So to make sure I understand this correctly… Does this mean that the Thunder would have actually been a better team the past two years if they had traded KD for Tim Thomas?

    Comment by Fred — November 23, 2009 @ 3:01 pm

  6. I think part of the confusion about the play call is that Belicheck made a mistake on 3rd down or 4th down by WHAT play he ran, not whether or not to go for it. Convincing people to eliminate this portion of his decision (why go 5 wide, why not leave a RB in the backfield, why not run on 3rd down if you know you’re going on 4th etc…) makes it a lot easier to think rationally about whether going for it was right or not. It also makes it harder for people to look at it as a hindsight decision I think.

    Comment by Eric B — November 23, 2009 @ 3:06 pm

  7. Not to nitpick, but MAKE + LONG/SHORT>1 seems like a bizarre way of expressing the decision to be made. Why not rewrite it as LONG > (1 – MAKE)*SHORT so that the two equation can be read directly as “(iff) odds of TD after punt exceed odds of failed conversion and short field TD”?

    It seems like that would be a more logical way to express it, particularly when attempting to sway someone (Simmons) with less of an eye for probability and statistics.

    Comment by John — November 23, 2009 @ 3:26 pm

  8. Great rebuttal – I almost stopped reading that particular Simmons column after the “one time per year does a comeback like this happen” line. It came off as such a stretch, like he was to reaching to find some stat to support his position. Thanks for the article – hope to read more like it in the future!

    Comment by Anton — November 23, 2009 @ 3:29 pm

  9. If you took an “average” player with a +/- of 0 (let’s say someone without any scoring prowess), and put him in place of Durant, I bet that player dips to -14 or something much worse because nobody on that team would be able to score. +/- is a fluke.

    Comment by dan — November 23, 2009 @ 3:38 pm

  10. Simmons needs to re-read the first couple of chapters of Moneyball. KD looks like an all-time great basketball player, but until his team wins like a star’s team should, he’s more like Stephon Marbury than Larry Bird. And remember that at his age, scouts (and observers in general) can imagine all the things they want in his future.

    Comment by Mike — November 23, 2009 @ 3:41 pm

  11. I cant speak for Bill Simmons (so I dont know if his view was the same as mine although I suspect it is) but regarding KD, it wasnt the stats saying that him being on the floor hurt the Thunder in the past 2 years that I found hard to accept (I actually think thats the kind of real gems stats should be aimed at finding) its that GIVEN this observation, Wayne, you decided (hypothetically of course) that you wouldnt want him on your team at all, even for free.

    Given KD’s age, his obvious talent and potential, surely it would be counter productive for you in this hypothetical GM role to use the +/- observation as “final” evidence against him without possibly investigating further for the reasons behind it (like Pick and roll D etc)? Its not the +/- numbers that I have a problem with it, its the assertion that you want him for free based SOLEY on the +/- figures. If the reasons behind his poor +/- are relatively easy to fix, surely you in this hypothetical GM role would be shooting yourself in the foot?

    As for the Pats, as suggested in this article, its a close call either way when you look at the stats. Therefore, while I certainly wouldnt argue the stats were “compeltely wrong” Id be hesitant to argue that the stats backed the Pats choice so strongly. Even with the above probability numbers, the case is relatively marginal at best and therefore, the payoff wasnt necessarily worth the risks etc.

    Comment by JP — November 23, 2009 @ 4:42 pm

  12. If Pau Gasol somehow causes Lamar Odom’s +/- numbers to improve, you’ll have to create a meta-+/- number that measures’ players’ effects on other players’ +/-

    Comment by J.D. Hastings — November 23, 2009 @ 5:02 pm

  13. Also, in Simmons’s section on Hakeem Olajuwon, he calculates that 50 x 100 = 50,000, so… I wouldn’t hold my breath on using math to convince him of anything he doesn’t already believe

    Comment by J.D. Hastings — November 23, 2009 @ 5:03 pm

  14. I second Jeremy’s comment. Bill clearly believes in supernatural influences and this is why he believes numbers don’t tell the whole story. He’s more interested in a player or coach’s “face” (i.e. “Peyton Manning Face” or “Alex Rodriguez Face”) than historical data on 4th and 2 attempts.

    I love alot of the Sports Guy’s stuff but he seems to be on shaky ground when he delves into anything involving the application of statistics to sports.

    Comment by Spencer — November 23, 2009 @ 5:04 pm

  15. Wayne – Got to clean this up. The typos and the change in the font size are very distracting. Other than that, a great read, which is more than I can say of the Simmons column. I agree with you 100% on this.

    Comment by Metsox — November 23, 2009 @ 5:15 pm

  16. Do you understand the concept of begging the question? To paraphrase
    WW/Stats Community: “Adjusted +/- says Durant was bad, Tim Thomas was good.”
    BS: “Basketball stats are an imperfect science at best. Only devout ADJ +/- followers would say KD is bad and Tim Thomas is good.”
    WW: “But the stats say they are good, thus they are good.”
    (Cut to shot of AFLAC duck after Yogi speaks) !?!? (And why cite to non-stat authority in Morey if you can cite a stat?)

    This may be a “pitching to the score” argument, but the NBA seems to be enough of its own unique beast: doesn’t the fact that KD was a young player on a young (not really in the championship hunt) team have some effect on these stats? If it can be (or has been) shown that there is no learning effect for playing as KD has played, in the situations KD played in, then this argument is bunk. But learning effects have to be considered (I’m sure there would be a distribution as with any other stat, some fast learners and some slow learners), and maybe +/- isn’t able to incorporate that, but then this shortcoming should be disclaimed.

    Also, you’re missing the greater point of his argument, which is that the stats don’t tell the entire effect of an NBA player on his team. These stats only speak to the effects of his on-court presence. If his off-court presence submarines players’ general disposition, chemistry, etc., this can have on-court effects. Where is that located in your Tim Thomas end-all-be-all statistic?

    You may be right, he may be a lunatic, but your reasoning is not without fault.

    Comment by Robert — November 23, 2009 @ 5:55 pm

  17. Classy Wayne. Very classy. When people get mad and shout insults, it just shows that they have no confidence in what they are saying. You’ve converted me for sure.

    Comment by Matthew — November 23, 2009 @ 5:59 pm

  18. Is there a good resource online for adjusted +/- numbers of any given player/team?

    Comment by CKnox — November 23, 2009 @ 6:07 pm

  19. The thing is, Simmons wasn’t really firing off insults to Winston. He was saying the system to determine these results is obviously flawed. And I have to agree. Look, anytime you try to bring math into sports there are going to be problems. There are too many variables to consider, and not everything is accounted for. Sometimes the math makes sense (example: LeBron’s ridiculous PER last year. Seeing him night in and night out, that math definitely didn’t lie), but, and this was Simmons’ main point, in sports like basketball and football, math cannot be taken as absolute truths.

    There are still factors of the game you have to be able to see first hand to truly rate them (and even then, it’s not really possible). I will give you a perfect example: Josh Smith. On paper, Smith is a great player. He has a ton of athleticism, he can rebound, block shots, he can do just about anything. But he wasn’t a smart player. Game I.Q. is not really something you can take into account with stats. This year, he is playing smarter basketball, and while his numbers are necessarily better than they had been in previous years, he is probably the main reason the Hawks are off to such a great start this season.

    Now, I know one of the main points (arguments?) Winston has made for the past couple of seasons is that Jason Kidd is a better fit than Devin Harris (or something along those lines). He had the numbers to back it up, and there’s really no arguing that the numbers do support his case. But what if the way he got to the numbers was the mistake? Are the Mavs a better team with Kidd? I don’t know. Are they the best team in the West, like they were in 06-07? Absolutely not. Is that Kidd’s fault, or are there other extenuating factors? Probably a little of both, though LA getting better had a lot to do with it.

    The point is, basketball remains a game that needs to SEEN to be able to comprehend. That was the point Simmons was making, and it is a point I can get behind…. especially when it involves Tim Thomas being a waste of space.

    Comment by Colin — November 23, 2009 @ 6:40 pm

  20. has a version of adjusted +/-

    Comment by wwinston — November 23, 2009 @ 6:50 pm

  21. [...] Winston got wind of Simmons’ shout out and responded on his blog. [...]

    Pingback by Bill Simmons vs. Wayne Winston — November 23, 2009 @ 7:17 pm

  22. Wayne,
    Can you test for and/or control for the factor that KD may have been in during the important minutes and out of the game during mop-up time where opponents’ defense would have been lax?

    Comment by Ben F — November 23, 2009 @ 7:19 pm

  23. [...] Winston got wind of Simmons’ shout out and responded on his blog. [...]

    Pingback by Bill Simmons vs. Wayne Winston | Football Picks — November 23, 2009 @ 7:34 pm

  24. we did that via impact rating and he looks even worse. this year he is fine however.

    Comment by wwinston — November 23, 2009 @ 7:38 pm

  25. we are not looking at points scored but margin of victory. Thomas surely made Gallo Harrington better.

    Comment by wwinston — November 23, 2009 @ 7:39 pm

  26. because this form lets us see that MAKE is more important and LONG/SHORT is virtually defense independent.

    Comment by wwinston — November 23, 2009 @ 7:41 pm

  27. we will do this in two weeks or so. Gasol has +10 rating so far.

    Comment by wwinston — November 23, 2009 @ 7:44 pm

  28. On the Belichik issue, you are completely right. Even fudging the numbers means its a close call either way at worst. It simply can’t be a terrible decision. If I go all in on a hold’em game with 49% chance to win, is it really a horrendous decision? Simmons is a Boston guy and I have noticed that it is the Pats fans that are the most disgusted with Belichick’s decision….which I find somewhat surprising given that Belichick also has a good number of “counter-intuitive” play calls that have had huge beneficial results and it is generally his aggressive playcalling that has brought him much success.

    I do think Tim Thomas is SLIGHTLY underrated like you say, but only because the perception is that he is worthless. But he is not a good player, but that is not the point. On Durant, I could not disagree more and I agree with Colin’s comment above. You simply have to watch football or basketball to give context to any statistic. Sure Durant took a lot of bad shots his first two years, but why? You have to watch the offensive ineptness of his teammates to have understood why. Sure they can hold their own for few minute stretches when Durant is off the floor, but they simply were not good enough at that point. And Durant did play awful defense…but it was his offense that kept them in a good amount of games. If you propose Lamar’s +/- may be negatively affected by not having Gasol in the lineup… how much more does it hurt to run with 4 teammates that simply aren’t good on offense and cannot create for themselves?

    No statistical metric will ever be able to fully be able to quantify the quality of basketball or football into a single number. You come up with the best system you can, but at times you will come up with strange results. You don’t have to trust the numers blindly nor throw out the entire system. You just have to apply context and ask the question “Why?”

    Comment by wiZo — November 23, 2009 @ 7:49 pm

  29. Simmons also has the bad habit of being definitive or absolute about things that are neither. He’s a jack ass in that regard.

    Comment by Jeremy — November 23, 2009 @ 8:33 pm

  30. Durant got hurt last year as the Thunder went into their stretch of ‘easy’ games. It figures that everyone else’s point differential would increase while his would not. Look at who they played while he was hurt. It wasn’t Durant’s injury that made their performance vs opponents improve, it was a reduction in the quality of their opponents. Adjusted +/- doesn’t take that into account and pretty much invalidates anything close to the conclusion you were trying to make.

    Durant was terrible defensively last year, and his improvement on that front this year is a large part of why OKC is a better team, if not yet a playoff threat.

    Comment by Olaf — November 23, 2009 @ 11:45 pm

  31. these are the best blog comments I have ever read in my life. There is no close second. special thanks to
    “John — November 23, 2009 @ 3:26 pm” for clarifying the make/long/short equation.
    “Comment by JP — November 23, 2009 @ 4:42 pm” for agreeing with me. +/- is terrific; KD DID hurt his team last year… but not taking a player with that kind of potential for free is crazy.

    Comment by johnny a — November 24, 2009 @ 1:19 am

  32. What disturbs me about the Durant analysis is that you say he has gone from being a liability to an all-star caliber player in the span of one summer. I’m sorry, but that just isn’t realistic or instructive. The difference between all star and libility is not pick and roll defending. I am willing to accept the notion that he is overrated, but if your analysis swings that wildly then perhaps your data isn’t as meaningful as you are claiming.

    Comment by Ledbury — November 24, 2009 @ 1:32 am

  33. Adjusted + – does account completely for strength of opponent.

    Comment by wwinston — November 24, 2009 @ 8:09 am

  34. Can you please let out the garbage time +/- minutes of KDs team last year? I want to see if that still backs up the whole story, cause I can remember a few games, where KD was sitting at the end of the 4th, where russel and green f.e. played. It is then totally plausible, that they cut the lead from 20 to 12 f.e. and so got a better +/- than KD, while they were playing against weaker opponents. My whole point is, that you have to see, against which opponents KD played (starting 5 vs. bench), to paint the picture. I just know one point from viewing KD: He is a heck of a player for a 20 year old!

    Comment by Sefan — November 24, 2009 @ 8:31 am

  35. We reduce impact of garbage time with our clutch rating. Durant also did poorly on this so it was not the garbage time.

    Comment by wwinston — November 24, 2009 @ 9:00 am

  36. As the saying goes, there are three kinds of lies: lies, damned lies, and statistics. The problem with stats like these in football and basketball is that they just can’t accurately gauge the entire situation. It’s hard to argue that the Pats had a 56% chance of success given that they were so out of sync that they had to burn two timeouts on the drive. The assertion that Tim Thomas is a (slightly) above average player is so laughable that it doesn’t require a rebuttal.

    Comment by Joe B — November 24, 2009 @ 11:14 am

  37. Your formula omits the possibility of an additional Pats possesion/score, which, due to time, would be more likely after giving the Colts a short field. I would think MAKE + LONG/SHORT + Increased likelihood of Pats Field Goal following Colts TD on short field would make a small, but relevant shift of a couple percentage points in Belichick’s favor. What say you?

    Comment by Rick — November 24, 2009 @ 11:41 am

  38. For Tim Thomas, I believe part Simmon’s point about his impact on the team is that his lack of hustle, bad attitude, etc. can negatively impact the ENTIRE team. This would not show up in plus/minus if he effected the overall attitude and work ethic of the team, thereby negatively effecting groups of five on the court that didn’t even include HIM. It may seem far fetched (I mean, these are professionals), but I think that’s what we mean when we say a player is a cancer–that s/he poisons the team. Again, this wouldn’t show up in plus/minus.


    Comment by Steve — November 24, 2009 @ 11:41 am

  39. Loved reading this post and the comments as well. Consider me a new fan.

    I think Ledbury has a good point, though. Could it be that there’s really that small of a difference between being a liability and an all-star caliber player? That seems impossible to me instinctively.

    The divide between positions on Belichick’s 4th and 2 call appear to me to be a clear divider on how people view sports. The more you believe supernatural, immeasurable qualities have an impact on the game, the more you think it was a terrible decision, and the more you trust in mathematical analysis the more you think it was a reasonable decision. Personally I fall somewhere in the middle – probably because sports would be no fun if I couldn’t at least pretend that Peyton Manning Face had no impact on the game – and feel that while it was a really risky move to call it totally unreasonable or moronic is unreasonable.

    Comment by Tim — November 24, 2009 @ 11:56 am

  40. You are right of course, but I think to make a decision in the heat of battle you would have to simplify things and Belichcick said he thought they could run out the clock so I do not think it is a big issue

    Comment by wwinston — November 24, 2009 @ 1:43 pm

  41. If he is a cencer why did D’Antoni trade for him with Knicks after coaching him with the Suns?

    Comment by wwinston — November 24, 2009 @ 1:43 pm

  42. I think you have to simplify things in such a situation unless you have a computer on the sidelines.

    Comment by wwinston — November 24, 2009 @ 1:44 pm

  43. So how did he make Gallinari and Harrington so much better, and he certainly played well in Phoenix.

    Comment by wwinston — November 24, 2009 @ 1:45 pm

  44. First let me preface my comment by stating that I do not believe under any circumstance the Patriots should be lambasted for going for it on fourth and two. Realistically, it was a difficult decision. When I saw the Patriots take the field for their attempted conversion, my reaction was “interesting, let’s see if this works”, not “idiotic”. Obviously their offense is the strong suit, and they had a chance to win the game in a manageable situation.

    My issue with your logic, Mr. Winston, is that your equation isn’t completely accounting for such variables as momentum (Colts were clearly winning the 4th quarter), home field advantage (how loud was it on the field), the pressure the Patriots were facing in a game that would have brought them within striking distance of the 1st seed in the AFC playoffs, the colt’s defense against 4th and 2′s (you mention the patriot’s success on offense, but what about the colt’s on defense? I would be interested to know this.), etc.

    Your statistical theories, at least for the face value, seem to water down many aspects of football/basketball that are vital to teams winning and losing.

    Comment by Jonathan — November 24, 2009 @ 2:00 pm

  45. You’re right about the Belichick call, of course, but that’s beside the point. Why are you kissing up so much? Simmons is an unfunny blowhard whose ignorance of sound statistical analysis is matched only by his disdain for stats-driven (as opposed to ‘intuition-driven’) analysis. He has no interest in playing the game straight. He’ll just blast you again if he responds at all, cherry-picking enough data to make it seem to the non-stats minded that he’s engaging on your level. (I feel sorry for the ESPN intern who had to run down all his irrelevant queries, by the way – that dude either had to bite his tongue or else learned a terrible lesson in hackery). Do you really like him as much as you claim, or are you just hoping that if you praise him enough he’ll link to you or put you on his podcast for some ‘friendly sparring’?

    Comment by Patrick R — November 24, 2009 @ 2:35 pm

  46. I have one problem with the KD analysis.

    Let’s assume we were going to evaluate the 50 best players in the NBA as voted by fans, sports writers etc… Among them we are reasonably likely to find one KD. That is, a player that rates poorly on Adj +/- despite almost everyone being convinced he’s extremely talented and already a very good ball player.

    That player would then be the focus of articles saying he’s not as good as he looks.

    So are the odds really 1 out of 100?

    I think not.

    If you picked one player at random, evaluated him, and he came up bad, THEN we could highly confident that the stats were telling us something significant.

    Comment by Italian Stallion — November 24, 2009 @ 5:53 pm

  47. I really do like most of his columns and love the podcasts

    Comment by wwinston — November 24, 2009 @ 9:44 pm

  48. Your objections should help determine your estimates of LONG SHORT and MAKE. Once these are determined the decision is pretty much set.

    Comment by wwinston — November 24, 2009 @ 9:45 pm

  49. I know Belichick thought he could run out the clock by making it (accounted for in formula), but I guarantee he considered that his defense could still stop the Colts (accounted for in formula) AND that the Colts might score within 1 minute leaving Brady and co. a full minute to reach field goal range (UNaccounted for in formula). If you’re going to go to the trouble to create a mathematical model for a decision process, you should include all the info that went into said decision. I think your analysis is awesome, and anyone who is as detailed as you should include every reasonable factor. Thanks for your posts and responses!

    Comment by Rick — November 24, 2009 @ 11:19 pm

  50. If he is a cencer why did D’Antoni trade for him with Knicks after coaching him with the Suns?

    Comment by wwinston — November 24, 2009 @ 1:43 pm


    Simple, he’s immensely talented and D’Antoni was the only coach he’s played hard for in 10 years. Teams will always take a gamble on a player with talent, look at Terrell Owens.

    Comment by Joe B — November 25, 2009 @ 1:00 am

  51. I’ve finally decided to stop arguing the value of intelligent statistical analysis towards sports. As a gambler, I can appreciate how much mainstream disillusionment works to my advantage. One thing I can be sure of is that numbers have made me a lot more money than my feelings ever have.

    The world needs more sports fans like Bill Simmons.

    Comment by Cole — November 25, 2009 @ 1:35 am

  52. On the Pats: You failed to notice that Simmons was arguing that the play they called in that situation didn’t make use of the longer field and thus effectively became a 2-pt conversion. Your statement that the short field makes it easier to defend the pass on the 2-pt conversion is precisely what he is saying – that they used a short field and made it into a play that has a much lower chance of succeding. If the odds are say 33% instead of 50%, it makes a big difference. Also, your analysis is sensitive to the ratio of LONG/SHORT; in one uses SHORT = 2*LONG, which is not unreasonable since the distance was probably going to be more than twice as long after the punt and time was running out, then MAKE would have to exceed 50% in order for going for it to make sense. He also was arguing that the consequences of losing in this way will have a bigger effect in future contests than if they lost the conventional way, but that hypothesis is rather difficult to test.

    A couple of people have pointed out that if the Colts scored quickly off the good field position then the Pats would have time to hit a last second field goal, but OTOH, if they went for it and succeded, the Colts still might have scored a TD in the last 30 secs when they finally did get the ball, assuming the Pats just kneeled down 3 times and didn’t try something even more risky like passing or handing off, which could lead to a turnover. These secondary possibilities probably largely offset.

    You mentioned that you polled college professors. Were any of these football coachs, too? Another argument Simmons makes is that this has never been tried before, so the odds are probabaly heavily against its success, since otherwise SOME coach would’ve tried it already. (I personally don’t find this argument too convincing, but it does imply that implicitly coaches’ assessment of the chance of success of that play was much less than 50-50.)

    Comment by Malcolm — November 25, 2009 @ 8:16 am

  53. As for what Cole said 2 comments ago about Simmons, the fact that his wife, who knows virtually nothing about football, creamed him both years he dared to go up against her betting on games tells you all you need to know.

    Comment by Malcolm — November 25, 2009 @ 8:20 am

  54. On KD and Tim Thomas: It is pointless to back your assertion about the relative value by using your +/- analysis if Simmons is questioning the value of that analysis in the first place. You must instead endeavor to show the value of +/- irrespective of its application to these particular cases first if you want to build a convincing arument.

    105 or 140 minutes of court time is not a particularly large sample – it’s only a few games worth.

    You have to tell us how you’re calculating your MSEs (standard deviations) before we can take them seriously. What assumptions are you making about the +/- distributions and how well do your residuals fit these distributional assumptions.

    Considering that OKC has only played a dozen games or so this year, how significant is your result that KD’s APM has improved so much? OTOH, if it really is so easy to improve APM so much in just one year, why wouldn’t you want someone with so much potential on your team for free?

    One weakness of +/- kind of statistics in particular is that they don’t tell you why a player has achieved his result, and thus how he could be doing better. At least box score statistics, when properly normalized, can give you a clue. But none of these statistics can substitute for actually watching games, which is what Henry did to see that KD was vulnerable to the pick and roll.

    Another problem with APM, when applied to individual players as opposed to lineups, is that it assumes a player’s value is intrinsic, i.e., independent of his teammates. But if so, do you find that a player’s APM remains the same as others on his team are in and out with injuries or move to the bench? Here’s an obvious counterexample: If you had 4 good wings and you added a mediocre center, you’d probably have a better team than if you’d added another good wing to the same group, because the center compensates better for what the other teammates lack.

    In order to get statistically significant results from APM you need to work with a lot of games over a period of time, but then players’ true abilities generally don’t stay constant over longer periods of time. So either you end up with results that have a lot of noise or you end up with averages over the past that don’t tell you how good a player is now.

    Another difference between APM and box-score metrics such as PER (which have their own flaws) is that fluctuations in a player’s performance from game to game produce fluctuations in PER, but at least these are attributable to the player’s own variability, whereas a player’s APM will fluctuate based on variations in his teammates’ and oponents’ performances as well, so it is much harder to use APM for shorter periods of time.

    Comment by Malcolm — November 25, 2009 @ 8:47 am

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