It’s not hard to figure out which players mean the most to their teams. There are plenty of advanced metric stats that show which stars really matter and which ones are less of a factor.
A simple look at the 2015-16 individual player +/- numbers for when they are on the court shows a very clear story. Steph Curry is the top player in the NBA in that metric. But there are two clear problems using a simple +/- chart to assess player value when it comes to pointspreads. First and foremost, it doesn’t factor in the value of the replacement player. And second, all the best +/- stats come from players on the very best teams.
The hard numbers don’t lie. When it comes to +/- stats, the Top 21 players in the NBA are on only five teams: Golden State, San Antonio, Oklahoma City, the LA Clippers and Cleveland. The superstars are well represented on that list – Curry, LeBron, Kawhi Leonard, Russell Westbrook, Kevin Durant, Chris Paul, etc. But you’ll also find the likes of Serge Ibaka, Andre Iguodala, Steven Adams, Patty Mills, JJ Redick, Boris Diaw and Matthew Delavadova on that Top 20 +/- list.
Nobody who actually watches the NBA would consider any of those players as Top 20 talents. And none of those guys – not a one of ‘em except perhaps Ibaka – would move the needle even a half point when it comes to moving a pointspread. Clearly, +/- stats are not indicative of pointspread importance.
What about one of advanced metric stats, their ‘Real Plus Minus’ This chart is certainly more valuable than the first one above, because it adjusts the impact of reserves down to the number of possessions played. On this list, you’ll still see the stars from the elite teams on top – Curry, Westbrook, Leonard, LeBron and Draymond Green are the Top 5. But you’ll also find the likes of Toronto’s Kyle Lowry, Sacramento’s DeMarcus Cousins, Atlanta’s Paul Millsap, Indiana’s Paul George, Detroit’s Andre Drummond and Chicago’s Jimmy Butler in the Top 20, all worthy inclusions.
But this list is clearly flawed as well. Kevin Love has not been the 13th most valuable player in the NBA this year. Andrew Bogut and his 20 minutes of playing time per game is not a Top 25 player. Atlanta’s bench scorer Mike Scott, and washed up player/coach Kevin Garnett both made the Top 40 here!
And the one key metric when it comes to pointspread adjustments – the difference between the star and his replacement – isn’t even touched with any of these +/- charts. That’s where subjectivity comes into the equation, and subjectivity isn’t something that advanced metric stats can adjust to very easily.
Steph Curry is the most valuable player to the pointspread in the NBA not just because of his amazing stats. It’s because there’s no other player like him. Shaun Livingston got the start when Curry missed two games right before New Year’s; Igoudala took some of Livingston’s minutes at the point off the bench. The markets made at least a five point adjustment for his absence in both of those games, a loss at Dallas and a win at Houston.
The only other player that moves the needle in a ‘five point adjustment when he’s out’ like Curry is LeBron. The Cavs only game without their superstar this year came at Miami. The line moved three full points after the expected absence of LeBron was announced, but even that doesn’t tell the full story, because the $$ came in against Cleveland on pure speculation, before the announcement. Richard Jefferson got the start in LeBron’s staid and it wasn’t pretty in a 15 point loss for the road team.
Let’s not forget that when superstars sit, their teammates often view the game as a night off. That’s what happened to Golden State when they got blasted at Dallas without Curry, and with the Cavs when they got blasted at Miami. There’s a legitimate psychological effect that varies by situation, often leading to relatively flat efforts for elite teams when their best player gets the night off.
It’s not hard to assess pointspread impact when it comes to superstars. I will visit this topic again later in the week, talking about the under-the-radar guys who don’t move pointspreads yet still have an enormous impact on their team’s collective energy and their final results.