Sunday, February 6, 2011

Stephen Curry: All-time Great Shooter?

Curry's shooting stroke is no secret, but I don't think people understand how great his shooting has been. He's leading the league now with a free-throw percentage of 93.7% at the age of 22. This is after his rookie year of 88.5%. Those percentages are nearly unprecedented. The only person who's had a percentage of 90% or above at a younger age is Kevin Durant, who made the seventh most free throws ever in a season at 90.0%.

The reason I'm thinking about this? Curry's career free-throw percentage is 90.7%, which is higher than current leader Nash's 90.41 and Price's 90.39%. And I can't think of a reason why he can't sustain this.

A few of the greatest shooters of all time have had similar seasons at slightly older ages, but looking at their free-throw percentage progression, each one of the top ten guys by percentage has improved as they age. On average they increase their career free-throw percentage by 0.35% each year. (This average was found by doing a linear regression by year of how their career free-throw percentage changed. R-squared values were generally around 0.75, and all were above 0.58. Only Rick Barry and Billups had sizeable standard errors.) What this means is that assuming he plays into his mid-thirties and he improves his shooting like the other greats, one can estimate he will end up with 95.3%.

95.3%. I agree that's implausible, and modeling this with linear regression of other players and comparing it to a guy's first two seasons has lots of flaws. But I think it highlights how great he's been and it's reasonable to assume a player with a good work ethic can become a better shooter over time, especially compared to his early 20's. One reason is that shooting is not the same type of skill-set that basketball players need for elite level quickness and jumping. Players may lose a step even in their twenties, but hand-eye coordination and muscle memory in training shooting can actually improve into a player's thirties.

Curry's three-point shooting hasn't even been mentioned yet. He's at 43.2%, which would be sixth all time behind; interestingly, his teammate Anthony Morrow occupies the top slot with 45.6%.

John Hollinger had an interesting article about figuring out the best shooter of all time. The methodology was simple: add free-throw percentage, three point percentage and two point percentage. This methodology works because it weights free-throws higher since they're more objective (you're not guarded and it's the same distance) and it can be used to compare eras where we didn't have comprehensive shooting information, like percentages for every spot on the court. Nash was at the top with a CSR (combined shooting rate) of 1.849, way ahead of Kerr and Miller's 1.812 and 1.807. Curry's CSR now is 1.823, which would be second all time.

Stephen Curry's ranking for all-time career percentages
Free-throw %:   1st
Three-point %:  6th
CSR:                    3rd (behind Morrow)

Anthony Morrow's ranking for all-time career percentages
Free-throw %:     1st
*Three-point %:  1st
CSR:                      2nd
*Note: qualifies

So the caveat here is that Curry doesn't have enough attempts to qualify for free-throw and three point percentage, but even that speaks in his favor because players generally improve over time. His shooting stats could likely improve. And his old teammate Morrow is taking a run at the record book too.

While old-timers love to complain about the lack of skill in today's game, recent evidence has proven otherwise. Ray Allen is about to become the career leader in three-pointers made. Nash has eclipsed Mark Price in free-throw percentage, as well as shattered the record for 50-40-90 seasons. Kyle Korver broke the single season three point percentage record. Jose Calderon broke the single season free-throw record. And Curry and Morrow, despite their ages, are poised to set some records even higher. The future is bright in the NBA.

(Note: It looks like some have recognized Denver's offensive efficiency, namely two John's in Hollinger and Krolik. But they didn't comment on how the player who takes the most shots is probably their worst shooter. However, I'm glad Nene got mentioned in the Nytimes.)