The Difference Between Measuring Defense in Basketball and Baseball
The April 6, 2009 issue of
Sports Illustrated contains an article by Albert Chen titled
Baseball's Next Top Models; Chen describes how baseball teams are using advanced statistics to ascertain which players are the best fielders at each position. The Tampa Bay Rays won the 2008 American League championship largely because they tremendously improved their defense by using advanced statistics as the basis for various personnel moves and for deciding how to most effectively deploy the players on their roster to maximize their defensive skills (for instance, they moved Akinori Iwamura from third base to second base not only because his defensive statistics are better at the latter position but also to make room for Evan Longoria to be called up as the new third baseman). Baseball statisticians have access to data that pinpoints where every single batted ball went and whether or not the fielder converted that play into an out. Although there are at least 10 players on a baseball field at any given time (one pitcher, eight fielders, one batter--assuming that there are no men on base), virtually everything that happens when the ball is in play can be broken down into a series of discrete, one on one actions: the pitcher throws the ball, the batter swings and, if he makes contact, a fielder attempts to catch the ball. Therefore, if one gathers together a large enough sample size of data, it is possible to create reliable models regarding pitchers, batters and fielders.
Obviously, basketball is a much more fluid and complex sport than baseball, at least in terms of constructing meaningful statistical models: even during an "isolation" play ostensbily involving only one ballhandler and one defender the other eight players on the court all have the potential to affect what will happen--the other four defenders may end up trapping and rotating, while the other four offensive players (depending on their size and skill sets) may be called upon to set a screen, cut to the hoop, spot up for an open jump shot or grab an offensive rebound. The play may result in an offensive rebound tip dunk or a made three pointer that never would have happened if the original ballhandler had not been talented enough to attract extra defensive attention but in the box score that original ballhandler may either receive credit for nothing (if he passes the ball and the recipient then swings it to a player who ultimately makes a three pointer) or he may even record a negative statistic (a missed field goal attempt) despite the fact that his actions directly led to the opening that created the putback opportunity.
Clearly, it is difficult for basketball statistics to fully capture what happens offensively; progress has been made in this regard but it is far from an exact science--and it is even more challenging to accurately measure basketball defense, particularly on an individual level. A perfect example of why individual basketball defense is tough to quantify took place in the first quarter of Boston's 106-104 game five overtime victory versus Chicago: Kendrick Perkins caught the ball on the left block versus Tyrus Thomas, spun baseline and scored a layup. TNT's Doug Collins noted that Thomas had positioned himself by Perkins' left shoulder (i.e., overplaying Perkins to force him to go to the baseline) because Perkins' best move from that spot is to go to the middle and shoot a jump hook; Thomas was supposed to receive help on the baseline--on an earlier play, help defender Derrick Rose stole the ball so easily from Perkins it looked like Rose was receiving a football handoff--but this time the help never arrived. How would a basketball "stat guru" evaluate that play in terms of Thomas' individual defense? Thomas' defensive rating would indicate that he allowed Perkins to score against him. Plus/minus data would award Perkins a +2 and Thomas a -2 and would also "indict" the other Bulls' defenders who were on the court at that time but would not reveal who was really at fault. A knowledgeable basketball observer would understand--as Collins immediately explained to the viewers--that Thomas did what he was supposed to do but that the help defender never arrived. Multiply this type of scenario over thousands of plays during the course of a season and it is easy to see why someone who watches basketball with understanding may come to a completely different conclusion about a player's value/skill set than someone who relies on nothing but numbers.
What about the success that Houston's General Manager Daryl Morey has had using advanced basketball statistics, as detailed in a
New York Times article that I discussed
here? If basketball statistical analysis is truly science and not pseudoscience, then it has to be based on the principles of
the scientific method:
- Ask a Question
- Do Background Research
- Construct a Hypothesis
- Test Your Hypothesis by Doing an Experiment
- Analyze Your Data and Draw a Conclusion
- Communicate Your Results
One "hypothesis" mentioned in the
New York Times article is that Daryl Morey and his staff of numbers crunchers can use advanced basketball statistics to devise a game plan to slow down Kobe Bryant, the 2008 MVP and a two-time scoring champion. If we consider the four games that Bryant's Lakers played against Morey's Rockets this season to be the "experiment," then the "data" show not only that Bryant's Lakers won all four contests (with a convincing 13.0 ppg differential) but that Bryant averaged 28.3 ppg versus Houston while shooting .530 from the field and .533 from three point range, exceeding his overall regular season averages in all three categories; oddly, Bryant's free throw percentage versus Houston was only .680 (well below his .856 regular season average) but I doubt that even the most ardent advocates of basketball statistical analysis will claim that this is a result of Houston's "free throw defense." So, the results of this "experiment" show that advanced basketball statistics have yet to enable Houston to defend Bryant more successfully than other NBA teams--and this is despite the fact that the Rockets have two of the best one on one perimeter defenders in the NBA (Ron Artest and Shane Battier) plus a 7-6 shotblocking center (Yao Ming).
Don't think that I am picking on Morey or Houston; as I wrote in my PBN article cited above, I appreciate that Morey is fully aware of the current limitations of basketball statistical analysis:
It cannot be emphasized strongly enough that Morey is not merely looking at spreadsheets and randomly assigning arcane values to certain combinations of numbers; statistics give him an indication of what to look for when he watches game film but he still has to watch game film to determine why players are putting up the numbers they do and to figure out what exactly those numbers mean.
In other words, Morey appears to understand the limits of a purely mathematical approach to the game and thus uses numbers to confirm what his eyes tell him -- and vice versa. This is a completely different approach from the one taken by far too many stat gurus who are so enamored with their formulas that they dismiss the importance of actually watching games -- perhaps because they are in fact not truly capable of watching basketball games with any real understanding of what is happening on the court.
It is a laudable goal for basketball statisticians to strive to analyze the sport as effectively as baseball statisticians evaluate baseball but when "stat gurus" and their buddies in the writing business act as if basketball has already been "solved" from an analytical/statistical standpoint they are actually hurting their cause more than helping it, because intelligent observers can plainly see that such claims are false. As Cleveland General Manager Danny Ferry
recently told me about basketball statistical analysis, "to just make decisions off of statistics would be a mistake but it can be an important part of the equation in basketball." It would be foolish for an NBA GM to not look at statistical data but it would be even more foolish for him to rely solely or even primarily on such data at this juncture; in the Perkins/Thomas example, it is much more useful for a GM or coach to know that Thomas did what he was assigned to do--and to find out which player missed the help assignment--than to get a spreadsheet filled with numbers detailing how many times Perkins scored in the post with Thomas as the primary defender, because without the proper context that data could be dangerously misleading if it influenced the GM or coach to make a negative evaluation of Thomas' defense.
Labels: basketball statistical analysis, Boston Celtics, Daryl Morey, Houston Rockets, Kendrick Perkins, Kobe Bryant, Shane Battier, Tyrus Thomas
posted by David Friedman @ 4:48 AM
Pippen Denies Specifically Criticizing Hinrich, Thomas
I mentioned in a recent
post that the
Chicago Tribune's Sam Smith quoted Scottie Pippen offering several blunt criticisms of various Chicago Bulls players. Smith
now says that Pippen angrily denies that his comments referred to specific players. Pippen claims that his remarks were simply general statements about the drawbacks of utilizing small guards and about the limitations of players who are not students of the game; he insists that Smith erred by applying Pippen's quotes to Kirk Hinrich and Tyrus Thomas. Pippen called up Smith and told him, "I've always liked Hinrich a lot and would have him finishing games. I think Thomas could play someday like I did and just needs to develop." The original quotes attributed to Pippen were quite harsh but they really did not create much of a stir--mainly because, as TNT's Charles Barkley and Kenny Smith noted on Thursday, they were true.
Although Smith begins his most recent article by writing, "Scottie Pippen says I owe him an apology," Smith neither apologizes nor does he categorically state that the quotes are accurate. Instead, he recalls the furor that accompanied the release of his book
The Jordan Rules and how all of that faded as the Bulls racked up victories and championships; the book's behind the scenes look at the team contained frank--but fair--portraits of the team's players and coaches and discussed Michael Jordan's competitiveness and how hard the coaching staff had to work to get him to pass the ball to lesser teammates. No one has denied the truth of these stories but not everyone liked that these things were brought to light for the general public to see.
It is possible that Pippen really did mean to speak in general terms and that Smith erred in applying the quotes to specific players. This is a little hard to believe because Smith has covered the NBA for years and has interviewed Pippen on numerous occasions. Would Smith really not be able to tell the difference between a quote about small guards in general and a quote about a specific small guard? One interviewing technique that I find helpful in such situations is to repeat back to the subject what he just said and confirm that this is what he meant. I get the impression that some writers--not necessarily Smith--don't do this because they don't want to give a subject the chance to modify a potentially inflammatory quote. One time, I was interviewing Paul Silas, then the head coach of the Cleveland Cavaliers, for an article that I was writing about Bob Dandridge, who Silas played against twice in the NBA Finals. Silas told me that Dandridge was "a talker." I interpreted that to mean "trash talker," which is completely at odds with what I know about Dandridge. Rather than just running with that quote, I expressed surprise and said to Silas that I thought that Dandridge was not a boastful player. Silas immediately clarified that by "talker" he meant someone who communicated with his teammates on the court, calling out screens and relaying other information. If I had not asked the follow up question then I could have ended up writing something--quite unintentionally--that would have misrepresented both what Silas thinks and how Dandridge acted. Fortunately, I made sure to get the complete story. Moments like that happen more often than you might think during interviews; it is very easy for an interviewer who is either unskilled--or deliberately manipulative--to create a wrong impression about what someone says. The best way to avoid problems is to do enough research to be very familiar with your subject (I knew that Dandridge was not considered a boastful player), ask good questions and, above all, listen carefully to the answers; some people are so focused on the next question on their list that they don't really hear the answer to their current question and thus don't realize that a follow up question is necessary to clarify something.
Although I am often skeptical of the reporting and analysis done by many writers, I trust Smith. I suspect that after seeing the quotes in print, Pippen felt badly about how harshly he had spoken and regretted saying what he did. Although Pippen shoots from the hip when he makes public comments, sometimes after further reflection he tones down his initial statement.
Labels: Chicago Bulls, Kirk Hinrich, Scottie Pippen, Tyrus Thomas
posted by David Friedman @ 3:01 PM
Scottie Pippen is No Diplomat, but He Knows Basketball
Scottie Pippen would like to coach the Chicago Bulls, the team that he helped lead to six NBA titles, and he does not understand "the key to the good 'ol boy system" that he believes is preventing him from getting a coaching job: "What's my disadvantage? No NBA coaching experience? Skiles' record with the Bulls wasn't that great. It doesn't take a rocket scientist to do what you've done your whole life. I've played basketball, run teams and won. They didn't put me at point guard because I could dribble good. They put me there because I could run a team. I wasn't the best dribbler, the best shooter. I wasn't a point guard. But I knew how to run a team."
Pippen told the Chicago Tribune's Sam Smith, "What experience do you need? You have assistants who have been there. If I made a mistake, I wouldn't be the first coach to make a mistake. I'd love the opportunity to be part of the organization now that Skiles is gone. I've won championships with this organization and been in the competition when everything was on the line. I was a coach on the floor. Why isn't that experience?"
Pippen also offered some blunt assessments of the skills and limitations of some of the current Bulls' players:
***Tyrus Thomas "dribbles better with his left hand than his right. He must have broken his arm when he was a kid. He shouldn't be dribbling. He should be a fetcher. Like Ben Wallace, (Joakim) Noah, go get the ball."
***Ben Wallace "doesn't know the game like Dennis Rodman did. Dennis knew how and why he got rebounds. So you keep on him (Wallace) or he doesn't play."
***Ben Gordon "(is) out there shooting for a contract...If there's two, three guys running at him, he still wants to make a shot. Those shots are out of position, your teammates don't expect them, you are not in position to rebound and get back. Taking bad shots is a sign of a lack of respect for your teammates. You think I'm going to run back if I know B.J. Armstrong is jacking it up? My shot is just as good as his. That's what players think."
***Kirk Hinrich "(is) guarding Kobe, Tracy McGrady, the best players. He's not that talented. Let him run the offense. But you can't have midgets running your backcourt. Little guards always put you in a vulnerable position. You've got to send help. It puts too much pressure on the defense."
***Luol Deng "(is) solid. But he doesn't have enough speed. He plays more upright, so it's tough for him to go out and guard smaller guys. I think Deng is on the verge of being a star. But all that money talk added pressure. Now he's trying to show 28, 29 teams what he's about instead of going out and playing."
***Andres Nocioni "(is) turning into Rasheed Wallace with the kinds of things he does on floor. It makes the officials turn on the whole team. And you stop getting calls."
Obviously, diplomacy is not Scottie Pippen's strong suit. I stood right next to him during the 2007 All-Star Weekend when he told a group of reporters, "If you ask people who understand the game, the GMs and the coaches, they'd rather have a Scottie than a Michael." As I explained, "there is in fact some truth to what he said--not so much that GMs would prefer Scottie to Michael but that they would prefer the way that Scottie played. Jordan was a more naturally gifted scorer but as a rebounder, playmaker and defender Pippen did not have to take a back seat to any midsized player--even MJ--and he consistently played, as Larry Brown would say, 'the right way,' supporting his teammates and trying to get them involved. He never felt the temptation that MJ often did to try to simply shoot his team out of trouble single-handedly."
Someone who hires Scottie Pippen to be a head coach may cringe once in a while at Pippen's blunt, brutally honest way of expressing himself--but isn't that a small price to pay in exchange for the wealth of knowledge and experience that Pippen has?
Labels: Andres Nocioni, Ben Gordon, Ben Wallace, Chicago Bulls, Kirk Hinrich, Luol Deng, Scottie Pippen, Tyrus Thomas
posted by David Friedman @ 6:15 PM
Bulls Idle Pistons to Capture Their First Win of the Season
Tyrus Thomas had a team-high 19 points and a career-high 14 rebounds as the Chicago Bulls beat the Detroit Pistons 97-93 to claim their first win of the season. Luol Deng added 17 points, while Kirk Hinrich shot poorly from the field (eight points on 3-11 shooting) but had a game-high 14 assists. Rasheed Wallace had a game-high 36 points, his most as a Piston and just six off of his career-high; he also tied Antonio McDyess with a team-high nine rebounds. The plus/minus stats told an interesting story, as journeyman Bulls forward had a game-high +10 mark. Coach Scott Skiles has said that Smith has been the team's most valuable player so far--admittedly not much of a distinction on a team that was 0-4 prior to this game--and Smith contributed 13 points and four rebounds, shooting 6-11 from the field. On the other hand, Bulls starting center Ben Wallace had a team-worst -8 plus/minus number; he finished with six points and seven rebounds in 25 minutes and did not play at all in the fourth quarter.
The Bulls outscored the Pistons 42-26 in the paint and outrebounded them 47-36. Those numbers tell part of the story of perhaps the most interesting subplot from this game, the battle between Chicago's young frontcourt players (Thomas, Luol Deng, Andres Nocioni, Joakim Noah)--with the aforementioned help from the veteran Smith and some early contributions from Ben Wallace--versus Detroit's veteran frontcourt of Rasheed Wallace, Antonio McDyess and Tayshaun Prince. Detroit did not re-sign Chris Webber, so Rasheed Wallace has shifted from forward to center this year, while McDyess has moved from being a reserve to taking Wallace's starting forward spot; both players rely more now on their wiles than their athleticism, which provided an intriguing contrast with Thomas and Noah, who are long on energy and hustle but short on experience. Detroit will have a good regular season record this year just based on muscle memory alone because the team has several current or former All-Stars but it is hard to understand why people seem to think that this team is better equipped to advance to the Finals than the last couple Detroit squads that fell short of that goal. Chicago matches up very well with this team, Cleveland beat Detroit four straight times in last year's playoffs and Boston has obviously looked very strong in the early going.
TNT's Charles Barkley and other analysts keep harping on the theme that the problem with the Bulls is that they rely too much on the jump shot but I don't think that is entirely correct. It is true that the Bulls do not have a stud postup player but when they are running their offense crisply they get a lot of dribble penetration to the hoop, leading either to layups or to open jumpers when the defense reacts to the dribbler. All good offenses attack the paint; having a great postup player is certainly a good way to do so, but relentless drive and kick dribble penetration can also be effective. As noted above, the Bulls owned a decisive advantage in points in the paint in this game even though they very seldom ran their offense through a post player.
The Bulls' slow start has attracted a lot of attention, partially because there were some high expectations for this team and partially because the Bulls have been mentioned prominently in trade rumors about Kobe Bryant. Chicago has been a slow starting team for the past several years and there is no reason to think that the Bulls will not have 50 or so wins by the end of the season. That is not to say that the early losses were not important--Chicago finished one game behind Cleveland last year and got a much tougher playoff seeding, so every game obviously can turn out to be vital by season's end--but every NBA team goes through a lull at some point; the Bulls just tend to go through theirs early.
There is always a lot of overreaction at the start of each NBA season but the only way to gauge if a team is really going to be as good or as bad as its early record suggests is to actually watch the team play and try to figure out why it is winning or losing more than people expected. Some teams start out with more difficult schedules or with a key player or two missing and those kinds of things even out over the course of the season. Other teams are, in Dennis Green's already immortal words, who we thought they were--San Antonio, Dallas, Houston are going to be good, while Portland, Minnesota, Seattle are going to struggle. Chicago and Detroit, as this game suggested, are very evenly matched and will both easily be Eastern Conference playoff teams, despite the sky is falling rhetoric that has been coming out of the Windy City in recent days.
Labels: Ben Wallace, Chicago Bulls, Detroit Pistons, Rasheed Wallace, Tyrus Thomas
posted by David Friedman @ 3:24 AM
