The NBA is a make or miss league, as cliché as it sounds.
Here at Nylon Calculus we have written at length about how randomness influences outcomes in the NBA. A season’s worth of 3-point attempts from a single player is rarely enough to evaluate changes in his shooting percentages. The defensive numbers of a player can also be influenced by the hot or cold shooting of opponents.
Chance affects the NBA season even though each team plays 82 games. So when it comes to a playoff series of, at most, seven games, it is not a surprise that randomness can play a big role. Seven games is far too little for shooting percentages to stabilize. A few players having a hot or cold shooting series can swing a series.
To illustrate this point, I calculated how many 3-pointers each player in the playoffs would be expected to hit, given their playoff attempts, if they had hit their usual percentage over the last three seasons. Below is the plot of expected 3-pointers made vs. actual 3-pointers made. I have highlighted the Top 4 players above and below expectations, as well as Paul George, Steph Curry and Russell Westbrook:
The worst shooting player is Ryan Anderson, who has shot 3 for 24 from distance. Based on his shooting skills, we would expect him to have hit nine of those 24 3-pointers. The next three are James Harden, Bradley Beal and Kyrie Irving, who all missed five more 3-pointers than we would expect.
The best shooting player has been Tony Snell, who is at five 3-pointers above expected, followed by Draymond Green, Norman Powell and Kawhi Leonard, who are all four 3-pointers above expected.
The calculation takes defender distance into account by separating the different defender distances and calculating expected number of 3-pointers based on the player’s 3-point percentages on these different distances, which means we have accounted for if a player is shooting more contested 3-pointers than usual.
On a team level, Houston has hit around 14 3-pointers less than we would expect, driven mostly by the cold shooting of Harden and Anderson, as we saw above, but also by Trevor Ariza being 3-of-16 from 3-point range.
Houston would have looked a lot better against Oklahoma City if they had hit those 3-pointers. It should be noted though, that eight of the 14 3-pointers that the Rockets are below expected on, came in Game 5, where they went 6-of-37, so it might not have affected the series as much overall if they had shot closer to their normal percentages.
The Washington Wizards have also suffered from cold shooting, which is especially damning against Atlanta — a team that in the regular season played great defense in a lot of areas, except that they gave up a lot of 3-pointers (28th in the league). The Hawks have not been quite as bad at giving up 3-pointerss in the playoffs (26.9 attempts per 100 poss. vs. 30.3 attempts per poss. in the regular season), and when they have, the Wizards have not been able to punish them.
In all likelihood, Kyrie will bounce back, Ryan Anderson will start hitting shots and Draymond Green will cool down. But maybe not. The playoffs are not long enough for all hot and cold streaks to even out. And one of these might just end up determining the season.