LeBron James' Rescinded Phony Triple Double is a Symptom of a Larger Problem
Intelligent NBA observers know that there are serious problems with the accuracy/meaningfulness of box score numbers, which by definition means that the so-called "advanced basketball statistics" that are cherished by "stat gurus" are also deeply flawed. Box score numbers are not only devoid of context--points scored by a bench player during garbage time of a blowout game count the same as points scored in the fourth quarter of a close game that will decide which team wins a division title--but they often are just flat out wrong. Faulty scorekeeping is a serious NBA problem; when I have charted Chris Paul's assists I have consistently found
that he is credited with more assists than he deserves--and it is
perhaps most telling that I have never found an instance when a player
was not credited with an assist that should have been recorded. The
scorekeeping errors only happen in one direction (i.e., padding totals as opposed to depriving players of assists that they rightfully earned) and I am not convinced
that this is primarily "home cooking," though that may play a part. NBA scorekeeping is either inherently sloppy or else there is a bias toward artificially inflating the numbers of certain players, perhaps with the intention of comparing today's stars favorably with stars from previous eras by making it seem as if today's stars are setting records that they are not really setting.
The latest publicly acknowledged example of NBA scorekeeping gone bad took place on Monday, when LeBron James supposedly posted 32 points, 12 rebounds and 10 assists while leading his Cleveland Cavaliers to a 118-111 victory over the New Orleans Pelicans. Upon further review, the NBA removed one rebound and one assist from James' totals. Both scorekeeping errors occurred during one continuous sequence: the incorrectly tallied rebound happened when a missed shot bounced off of James' hands into the hands of his teammate Tristan Thompson, who controlled the ball and should have been credited with the rebound. Thompson then made an outlet pass that resulted--after many dribbles--in a Kyrie Irving fastbreak layup. No assist should have been awarded on that play but instead the scorekeeper gave James an assist, which makes about as much sense as giving Mark Price an assist on the play.
One can dismiss this as "home cooking" or say that Cleveland's official scorekeeper just had a bad night but the reality is that egregious errors regarding LeBron James' box score numbers do not only happen in Cleveland. This is the third phony LeBron James triple double that the NBA has corrected, with the first one happening on April 1, 2006 and the second one happening in Madison Square Garden on February 4, 2009. Scorekeepers would not be making such obvious mistakes unless this kind of box score padding is an accepted practice. The NBA claims that it regularly checks game film to make sure that the box score statistics are accurate but--in light of the numerous uncorrected box score mistakes that I have found in just a handful of Chris Paul's games--it seems more likely that the only reason LeBron James' phony triple doubles were rescinded is that observers outside of the NBA publicly called attention to these outlandish mistakes. Meanwhile, routine errors that are not publicized become part of the sport's historical and statistical record.
Labels: "advanced basketball statistics", "stat gurus", assists, Chris Paul, LeBron James, triple doubles
posted by David Friedman @ 6:13 PM
Charley Rosen Explains Why Statistics Can be Very Misleading
The title of Charley Rosen's article about the limitations of basketball statistics says it all:
The Numbers Game is Fraudulent. The two part series deserves to be read in its entirety but here are some choice excerpts to whet your appetite (the passages are not numbered in the original piece):
1) Yet even as Sabermetrics has become the latest craze in the NBA (as per the recent hiring of the stat-crunching John Hollinger by Memphis) there are many fallacies in this way of evaluating
basketball players. The primary one being that most statistics tally what happens when a player either has the ball in his possession or is in close proximity to the ball. Since there are 10 players on the court, 80-90 percent of the game is ignored.
Consider assists: Used to be that a pass-catch-shoot-and-make was the only sequence that led to an assist. Nowadays, an assist can be awarded when the pass-recipient takes one dribble and two steps before his make.
2) Points scored is another misleading number. Points racked up by players on bad teams are relatively meaningless. It’s when a player scores that really counts, plus the circumstances. Amassing stats on how many fourth quarter points somebody scores, or how many times he scores in the last two minutes of a close game, etc. are also limited evaluations. Did a player score because a defender missed an assigned rotation? Or the player grabbed a teammate’s airball and wound up with an uncontested layup? Or was it a breakaway dunker created by a teammate’s steal, offensive rebound, and or perfect outlet pass?
3) Let’s examine minutes and games played. In NBA.com, minutes are given in whole numbers. This means a guy who plays one second and one who plays eighty-nine seconds are both credited with one game and one minute played. This eighty-eight second difference could conceivably include at least four possessions, and could therefore be the difference between a totally insignificant appearance and a critical one.
4
) Now we come to my favorite group of people...According to Ed Rush, the one-time supervisor of NBA officials, the calls made by the league’s refs are correct 92 percent of the time. But that means that eight percent of fouls and infractions called are erroneous – even with late-game access to tape replays. Plus, Rush offered no approximation of how many times the refs err by not tooting their whistles...
If the refs have a distorted view of the game, then statistics such as free-throws attempted, fouls, turnovers, and even wins and losses are anything but objective.
So what are we left with?
Free-throw shooting. Three-point accuracy.
To truly judge the effectiveness of any given player, disregard the numbers and disregard the ball. Instead watch what he does when he doesn’t have possession or isn’t even in the neighborhood of the ball. Does he set weakside picks? Make cuts that open up space for a teammate? Make the pass that leads to an assist pass? Box out? Make appropriate defensive rotations? Get back on defense? And so on.
After all, in no circumstances can numbers ever measure the human spirit.
Rosen's point about assists is particularly relevant and also easy to verify; Chris Paul is indisputably a great passer but I have repeatedly
documented that his assist totals are inflated. I don't know if the NBA has unofficially broadened the definition of an assist to the extent that the statistic is rendered almost meaningless or if certain scorekeepers favor home players and/or star players but it should be obvious that if the raw box score statistics are not trustworthy then the so-called "advanced basketball statistics" must be taken with a heavy grain of salt.
Many "stat gurus" are all too willing to ignore the problematic nature of box score statistics while at the same time insisting that their proprietary "advanced" numbers are infallible but Dean Oliver is one researcher who consistently communicates in a very measured tone about the limitations of "advanced basketball statistics." Oliver's recent
ESPN.com article is a welcome departure from the haughty tone and wildly outrageous claims that far too often characterize the writing produced by proponents of "advanced basketball statistics." Oliver has high hopes for the future of "advanced basketball statistics" but he also candidly admits, "The problem with player value metrics is that there is little to
validate them, meaning that no metric has established itself as clearly
the best. Metrics couldn't even be fairly compared. As each new metric
has been developed, it has served mostly to complement traditional
scouting, a way to reality check when subjective opinions formed by
watching and hearing about players were going too far astray." Oliver believes that, for now, "advanced basketball statistics" are more valuable in terms of evaluating a team's effectiveness and best lineup combinations as opposed to producing allegedly definitive individual player evaluations.
Labels: "advanced basketball statistics", assists, Charley Rosen, Chris Paul, Dean Oliver
posted by David Friedman @ 2:29 AM
Charting Chris Paul's Assists Versus the Golden State Warriors
On several occasions, I have
charted the assists that have officially been credited to various players in order to determine how accurate the NBA's "official" assist totals are. Last night, Chris Paul authored a spectacular performance as his L.A. Clippers defeated the Golden State Warriors 126-115: Paul scored 42 points, dished off 15 assists and swiped six steals, becoming the first player to post 40-15-5 in those categories since the NBA began officially recording steals in the 1973-74 season--but did all of Paul's assists fit the strict rulebook requirements for an assist? It is no secret that NBA scorekeepers often employ a very liberal definition of an assist; here is the official description of an assist, as posted at NBA.com in 2002 (the rule has not changed since that time):
An assist is a pass that directly leads to a basket. This can be a pass to the low post that leads to a direct score, a long pass for a layup, a fast break pass to a teammate for a layup, and/or a pass that results in an open perimeter shot for a teammate. In basketball, an assist is awarded only if, in the judgement
of the statistician, the last player's pass contributed directly to a made basket. An assist can be awarded for a basket scored after the ball has been dribbled if the player's pass led to the field goal being made.
The last sentence brings some subjectivity into the matter but old school scorekeepers would not award an assist on a play in which the recipient of the pass clearly did the bulk of the work to get open.
Here is my take on Chris Paul's 15 assists versus the Warriors:
1: Blake Griffin dribble drive, 11:02 1st Q: Correct, but borderline; Paul passed to Griffin, who received the ball at the free throw line, made a slight fake, took one dribble and scored. Griffin made an immediate attempt to score after catching the ball--so the assist has some validity--but the play could also be interpreted as a one on one move, not an assisted basket.
2: J.J. Redick fastbreak layup, 7:40 1st Q: Correct; Paul passed to Redick, who scored an uncontested fastbreak layup.
3: Blake Griffin drive, 6:07 1st Q:
Incorrect; Paul passed to Griffin on the right wing and Griffin made a fake, took four dribbles and made another fake before scoring a layup. Giving Paul an assist on this kind of play is such ridiculously bad scorekeeping that it makes one question the validity of the assist statistic, because Paul had nothing whatsoever to do with Griffin scoring on the play. Griffin created the shot entirely for himself.
4: DeAndre Jordan dunk, 5:48 1st Q: Correct; Paul lobbed the ball to Jordan for the dunk.
5: Jared Dudley jumper, 5:13 1st Q: Correct; Paul fed Dudley for a catch and shoot jumper.
6: Blake Griffin jumper, 4:28 1st Q: Correct; Paul inbounded to Griffin, who held the ball briefly before nailing a jumper. A very strict scorekeeper might not award an assist because Griffin did not make an immediate attempt to score after receiving the pass.
7: Jared Dudley three pointer, 4:19 2nd Q: Correct; Paul passed to Dudley, who immediately fired away from long distance.
8: Jared Dudley fastbreak layup, 3:19 2nd Q: Correct; Paul fed Dudley, whose layup attempt was goaltended by Andre Iguodala.
9: J.J. Redick jumper, 1:44 2nd Q:
Incorrect; Paul swung the ball to Redick, who used a pick and took two escape dribbles before nailing a tough, contested shot. Redick created the shot opportunity for himself, as opposed to the shot being created by Paul's pass.
10: Blake Griffin fastbreak dunk, 5:03 3rd Q: Correct; Paul lobbed the ball to Griffin for the dunk.
11: Blake Griffin fastbreak dunk, 4:47 3rd Q: Correct; Paul lobbed the ball to Griffin for the dunk.
12: Blake Griffin fastbreak dunk, 4:31 3rd Q: Correct; Paul lobbed the ball to Griffin for the dunk.
13: Jamal Crawford three pointer, 9:44 4th Q: Correct; Paul passed to Crawford for a catch and shoot jumper.
14: Jamal Crawford layup, 8:10 4th Q: Correct; Paul inbounded to Crawford for an uncontested layup.
15: J.J. Redick three pointer, 3:11 4th Q: Correct; Paul dished to Redick for a catch and shoot jumper.
Two of Paul's assists were incorrectly scored, one was a borderline case and the remaining 12 were clearly legitimate. This is the seventh time that I have charted Chris Paul's assists; in those games, he has been officially credited with 87 assists but only 70 of those assists comply with the rulebook definition--and that includes several borderline plays. Why does this matter? Assist totals are used by some commentators as a way to evaluate who are the league's best passers--and "stat gurus" use raw assist totals as part of their "advanced basketball statistics." Thus, if the raw assist totals are inflated/inaccurate, it is not appropriate to rank passers based on assist numbers and the "advanced basketball statistics" have to be taken with a grain of salt because the basic, raw statistics used to create the "advanced" numbers may not be correct.
Labels: assists, Chris Paul, L.A. Clippers
posted by David Friedman @ 4:38 PM
Flawed Box Score Numbers Can Lead to Faulty Conclusions
It has been a while since
I charted a player's assists for an entire NBA game but a play from Boston's 105-89 victory over Denver on Wednesday night caught my eye: Rajon Rondo passed the ball to Ray Allen in the right corner, Allen took two dribbles, drove from behind the three point line to the hoop, made a contested left handed layup--and Rondo received an assist! While it is true that technically an assist can be awarded even if the shooter dribbles after receiving the pass, an assist is supposed to be a pass that leads "directly" to a score. There is nothing special about making a routine pass to the corner and watching a future Hall of Famer execute an excellent move. An assist is supposed to reward the passer for helping to create a shot, not for simply being the last player to handle the ball before someone else shoots.
Some people may dismiss my concerns about the authenticity of NBA assists by looking at players' home/road splits, arguing that this all evens out, but I reject that contention for two reasons:
1) I have never suggested--and do not believe--that the primary problem is "home cooking"; I think that the assist standards have been lowered across the board (even though the official definition of an assist has not been changed) and I also strongly suspect that scorekeepers are more apt to give borderline (or even bogus) assists to players who are perceived as elite playmakers than they are to players who are not perceived that way. In other words, if Glen Davis had made the pass that Rondo made to Allen I doubt that Davis would have received an assist, even in Boston. The reason I say this is that if assists were handed out on every such play then almost every field goal in the league would be classified as an assisted field goal and that is not the case, though the number of assisted field goals has trended upward in recent years--a strange phenomenon considering how much of the NBA game consists of post up plays and isolations.
2) If, as I suspect, elite playmakers receive a certain benefit of the doubt across the board then things do not really even out over the course of the season--and this should be a great concern to both "old school" journalists/historians as well as to the "stat gurus."
This type of thing is one reason that I do not trust "advanced basketball statistics"; the "stat gurus" create formulas that not only contain various flaws/biases but they are also using basic numbers (i.e., box score statistics) that are not completely reliable. As I have said many times, it is much more valuable to have a player who draws a double team and makes the correct initial pass that ultimately leads to an open shot on the weak side than to have a player who racks up high assist totals because he handles the ball all of the time and/or he benefits from lax scorekeeping standards.
I thought that Chris Paul was the best point guard in the NBA a couple years ago even though my research strongly indicated that his assist totals were heavily inflated and I think that Rajon Rondo is one of the best point guards in the NBA now even though I don't believe that he is legitimately averaging over 14 apg--but until the NBA vastly improves its scorekeeping standards I will look with a jaundiced eye at the most subjective box score numbers (assists, steals, blocked shots, turnovers) and I will also be most suspicious of "advanced basketball statistics" that are based on those faulty numbers.
Labels: "advanced basketball statistics", assists, Chris Paul, Rajon Rondo
posted by David Friedman @ 4:37 AM
