Posted by Neil Paine on June 17, 2010
At first glance, Kendrick Perkins' knee injury early in Game 6 may seem like only a minor setback for the Boston Celtics -- after all, Perkins has scored just 8.5 PPG in the Big Three Era, and while his rebounding and defense are solid, he's never finished in the top 10 in RPG or garnered All-Defense honors. However, despite his lack of box score presence, Perkins has been highly important to the Celtics' chances this season: when he plays less than 22 minutes in a game, Boston is 5-8, including Tuesday's ugly loss and a similar beatdown suffered vs. Orlando in the Conference Finals when Perkins was limited by foul trouble.
We can really illustrate Perkins' hidden importance by looking at the Plus/Minus numbers. When Perkins was on the court for Boston this season, the Celtics outscored their opponents by 7.2 points per 100 possessions; when he wasn't playing, that number was only +0.2, a difference of -7 pts/100 poss. The same story has been true since Perkins became a regular starter in 2006-07: putting together a rudimentary game-by-game "with or without you" regression (similar to what I did in this post) between team HCA-adjusted PPG differential and whether or not a player played 17 minutes in the game (the MPG that usually indicates a "contributor"), Perkins shows up as adding +2.18 PPG to Boston's differential when he's a contributor vs. when he plays limited minutes or less.
Meanwhile, Perkins' Game 7 replacements, Rasheed Wallace and Glen Davis, don't fare nearly as well by the WOWOY metrics. Despite Davis' heroics in Game 4, he and Wallace have been Boston's two worst players by net on/off rating during the playoffs. Wallace has been particularly toxic for the Celtics all season -- the team played 5 pts/100 poss. worse when he was on the floor, as evidenced by his recurring appearance in the Celts' worst lineup combinations. Davis & Wallace look better by the 4-year WOWOY regression (Davis is +1.36, Wallace is +0.47), but neither has the ability to positively impact the game the way Perkins does. Without his presence, and playing on the road (home teams win Game 7 80% of the time), the Celtics appear to be in dire straits tonight.