On Tuesday July 21, 2009 the Timberwolves traded Sebastian Telfair to the Los Angeles Clippers. Most commentators believe the Wolves thought that draft picks Johnny Flynn and Rickie Rubio would be their great guards of the future. I am sure the Timberwolves did not realize that in Telfair they already had an outstanding point guard. Traditional NBA player metrics obscure Telfair’s value. For example, in ESPN commentator’s John Hollinger PER rating Telfair scored a 12.1 PER rating, well below the average PER rating of 15. My partner Jeff Sagarin and myself have rated players and lineups for the Dallas Mavericks for 9 years. We believe a player’s value is based on how he helps the team play well or poorly; not his individual box score statistics.
Let’s look at how the Wolves2008-2009 performance varied based on Telfair’s presence or absence in the game. The following table shows for each player on the team how the Wolves performance varies based on whether Telfair is in or out of the game.
Telfair In Telfair Out
Foye 3.2 -4.3
Jefferson 2.35 -4.89
Love -2.54 -7.79
Miller 1.22 -7.87
Gomes .88 -9.62
For example, when stud center Al Jefferson was in the game with Telfair, the Wolves played 2.35 points per game better than an average NBA team. However, when Jefferson was in the game and Telfair was out, the Wolves played 4.89 points worse than average. Looking at all numbers in the table makes it clear that Telfair has a very favorable impact of the Wolves team performance. Overall with Telfair in the Wolves were an average team while with Telfair out the Wolves played 7.35 points worse than average. The amazing thing is that Telfair makes under $3 million per season!
I hope this post convinces you that box score stats are only the tip of the iceberg!
Our rating system tells us that despite his poor statistical profit, during the 2008-2009 season Telfair played about 6 points per game better than an average NBA player.
ESPN’s power rankings have the Dodgers, Red Sox, Yankees ,Angels and Rangers as the top teams in baseball. When we try and find the set of rankings that best fit the scores to date (July 12) we find a different story. The top 5 teams based on scores are the Red Sox, Dodgers, Tampa Bay Rays, Yankees, and Angels. Best hitter’s parks are the Rockies and Diamondbacks home fields and best pitcher’s parks are the Dodgers and Padres home fields. Best hitting teams (after adjusting for parks) are Indians, Angels and Dodgers while best pitching teams are Giants, Mariners and Red Sox.
The two best parks for hitters in the NL are thin air Colorado (a team scores 1.19 more runs than average there) and Arizona (a team scores 1.07 more runs than average there). The two best pitcher parks are the Mets City Field (teams score .86 runs less than average there) and Dodger Stadium (teams score .75 runs less than average there).
After adjusting for the park, the Brewers have the best offense in the NL (.6 runs better than average). The Reds have the NL’s worst offense (.74 runs worse than average) followed by Arizona (.71 runs worse than average).
So far this year (through July 1)The Tampa Bay Rays have scored around 5.5 runs per game, the most in the American League. Does this mean they are the best hitting team in the AL? Not necessarily. It all depends on whether or not their home field is a “hitters” or “pitchers” park. Using techniques described in the Chapter 40 of my upcoming book Mathletics we determined Park factors (a concept pioneered by the famous Bill James) for all parks during the 2009 season. We found, for example, that after adjusting for abilities of teams hitting and pitching a team tends to score .29 runs per game more than average when playing on the Rays home field. After adjusting for each team’s Park Factor we find that the Indians are the best hitting team in the AL, with their offense being .89 runs per game better than average. The best pitcher’s park in the American League this year is Cleveland while the best parker for hitters is Minnesota’s home park.