Apparently it’s the season of athletes making statistically unsupported comparisons to their peers. Back in May, Patrick Peterson claimed superiority over Richard Sherman in the NFL (something that, according to the numbers — is dubious), and now Golden State Warriors guard Stephen Curry told Dan Patrick Tuesday that he thinks he’s a better offensive player than LeBron James:
A better offensive player, me or LeBron? That’s the first time I’ve ever been asked that question … Me. He obviously demands a lot of attention on the floor, but I like to say I can distribute, get my teammates involved and be a playmaker as well.
With all due respect to Curry, a true offensive force in his own right, this is another case where the majority of statistical evidence doesn’t do the challenger any favors.
According to the advanced box-score metrics, James spent the 2013-14 season outclassing Curry in usage rate, scoring efficiency, offensive rebounding, avoiding turnovers and drawing fouls. The only offensive areas in which Curry beat James were jump-shooting — Curry made 42 percent of his 3-point shots and 49 percent of his midrange jumpers; James knocked down those shots at rates of 38 and 39 percent, respectively — and passing (whether measured by assist percentage or SportVU’s optically tracked passing metrics).
But James is no slouch in terms of distributing the ball, either; he ranked 19th among qualified NBA players in assist percentage a year ago. Distance shooting is really the only offensive category in which Curry claims a substantial edge over James — and it’s an advantage mitigated by the fact that James’s shot distribution skews so heavily toward easier shots at the rim. So Curry is a better long-range shooter than James, but James doesn’t take that many long-range shots.
Zooming out, James’s personal offensive rating was higher than Curry’s even though James used a higher proportion of his team’s possessions (so subscribers to skill curve theory would have a hard time siding with Curry in this debate).
Case closed? Not yet. There have been instances when such box-score-based metrics fail to tell the whole story, and players with gaudy combinations of usage and efficiency don’t always have the impact we’d predict from their individual stats. These are the kinds of incongruities that ESPN’s Real Plus Minus (RPM) is supposed to detect. RPM estimates a player’s effect on his team’s efficiency after accounting for the quality of his teammates, opponents and a host of other variables.
By RPM, James was easily the offensive player who had the most impact in the NBA last season. Curry was second, slightly outpacing reigning MVP Kevin Durant.
The comparison gets a little more interesting, though, when you look at these adjusted Four Factors ratings, which apply the same technique — estimating a player’s on-court impact via regression — to the four essential barometers of a team’s offensive performance: effective field goal percentage (which adjusts ordinary shooting percentage for the fact that 3-pointers are worth 1.5 times as much as 2s), turnover percentage, offensive rebounding rate and free-throw rate.
In two of the four factors, James and Curry exert similar degrees of influence: Both boost team shooting percentages and reduce team turnover rates at levels greater than 95 percent of all NBA players. And despite his inferior individual offensive rebounding numbers, Curry is also associated with a much better rate of team effectiveness on the offensive glass than James is. This is probably due in part to the increased likelihood that 3-pointers result in “long rebounds” which can be rebounded more readily by the offense (of course, Miami’s incredibly low offensive rebounding percentage — at least some of which was part of a conscious strategy — bears mentioning).
Through this lens, the biggest disparity between the two players is in free-throw rate: James was in the 99th percentile in that category, while Curry ranked in the 54th percentile. But free-throw rate is the least important of the Four Factors. Crafting an overall average based on the suggested weights for each category, Curry would actually place slightly ahead of James on offense (even if the overall adjusted plus/minus ratings generated by the same data set have James at No. 1).
That would be an anomalous ranking, however, as the vast majority of advanced statistics side with James in this debate. The more interesting tidbit from such analysis might just be that Curry is within striking distance in most of the numbers, and that, statistically, there’s a good case to be made that Curry is superior on offense to Durant. James’s statistics are too overwhelming to be surpassed, but Curry is as close as anyone in the game.