LaMarcus Aldridge did something unusual in last night’s overtime loss to the Oklahoma City Thunder: he scored 39 points. The Portland Trail Blazers forward, who is likely to be chosen an All-Star for the first time when reserves are announced on Thursday, ranks fifth in the league in scoring at 23.7 points per game. Yet Aldridge has scored 30-plus points just three times this season; Monday was the first time all year he’s topped the 35-point mark. He has fewer 30-point games than Chris Bosh, who averages 19.7 points per game.
The difference between the two players is consistency. Aldridge has scored at least 20 points in 19 of his 25 games (as compared to 11 such games for Bosh) and has yet to score fewer than 13 points in any game. Aldridge’s splits this season are essentially identical. Per Basketball-Reference.com, he averages 23.7 points at home and 23.8 on the road. He averages 23.6 points in wins and 23.8 in losses. On no day of the week has he averaged more than 25.3 points or fewer than 20.8.
It’s no surprise, then, that when Tom Ziller of SBNation.com looked at consistency among the NBA’s leading scorers last week, Aldridge ranked third, trailing superstars Kevin Durant and LeBron James. What Ziller calls “volatility” has been termed “shake” in past research on the issue by Benjamin Golliver of Blazersedge.com–a blog featuring Blazers news and analysis. Both are user-friendlier ways of referencing the statistical concept of coefficient of variation, which improves upon the familiar standard deviation by allowing us to better compare scorers with different averages. (That is, a point of deviation per night is much more meaningful for a player who averages five points per game than one who averages 25.)
Before last night’s game, Golliver put together shake ratings for Aldridge and retired Portland star Brandon Roy throughout their careers. Here’s what those look like graphically:
In the past, Golliver has noted that Aldridge wasn’t given enough credit for his consistency. His numbers tracked closely to Roy’s between 2007-08, when he broke into the starting lineup full time, and 2009-10. Last season, a hobbled Roy was physically unable to produce consistent efforts, forcing Aldridge into the role of go-to scorer. Really, last year’s mark for Aldridge doesn’t do his performance justice. In this as in most everything else, Aldridge had two different seasons–a relatively disappointing start followed by an All-NBA finish. From Dec. 15 onward, Aldridge’s shake was 23.1, as compared to 28.1 over the full campaign. This year, Aldridge’s shake has dropped again to 18.1, making him far more consistent as a scorer than Roy ever was.
(Note that these numbers differ slightly from Ziller’s because Golliver is using absolute difference, rather than squaring the differences as standard deviation does.)
Ziller left open the question of how valuable consistency is among leading scorers. My answer, as it always is with consistency, is “it depends.” Dean Oliver has done phenomenal research on the meaning of consistency in basketball, and has concluded that it’s positive for good teams, but negative for bad teams. Think about it this way: a player like Monta Ellis (one of the least consistent 20-point scorers, per Ziller) is liable to win the Warriors some games with his hot outings. When he struggles, well, Golden State was probably going to lose anyway. This is a legitimate reason to believe that Ellis, and players like him, are more valuable on bad teams.
Put Ellis on the Heat, by contrast, and his bad nights might mean shooting Miami into a loss. When he goes off, well, the Heat probably would have won anyway. So a consistent scorer like James is much more useful to Miami, leaving aside their varying levels of efficiency.