Why Assists Are A Useless NBA Stat

In a year where Russell Westbrook is averaging a triple-double while being only third in the league (behind James Harden and John Wall) in assists, yet at the same time putting up the highest assist percentage (as in percent of teammates’ baskets assisted while he’s on the floor) by a player not named John Stockton in NBA history, and while all three guys I just mentioned are on playoff teams, we need to ask and answer one simple question.

Is ball movement really all it’s cracked up to be? As in, do assisted baskets have greater effect on wins than unassisted baskets?

(Ed. note: This piece originally ran April 5, 2017 and stats are current for the 2016-17 season up to that date.)

Now, nobody’s arguing that a player getting a steal and taking it coast-to-coast for a dunk is a bad thing, nor is anyone trying to make the point that a big man grabbing an offensive board and slamming it home is somehow detrimental to team basketball. But with offensive rebounds rare, putbacks rarer, and run-of-play fast break steals rare enough that making one all but ensures you’ll be on the SportsCenter Top 10 that night if you dunk it with flair, let’s assume that most unassisted baskets come from one-on-one moves or off screens in the halfcourt. Think DeMar DeRozan or Steph Curry, not Rudy Gobert.

Luckily, this is real easy to figure out. Just take assists, divide them into overall field goals made, sort them, and correlate them with wins. Because NBA.com makes this a bit easier than Basketball Reference, we’ll use the league’s tally this time.

The first thing that jumps out at you is that the Golden State Warriors are, as they were last year, the best team for assist percentage, and sure enough, they have the best record.

Trouble is, the data is noisy as hell. The worst team for ball movement leading to baskets is the Toronto Raptors, yet they’re the current three seed in the East. Philadelphia is third in the league in assist percentage, but 28-50 is no way to go through life, even if it is winning more in one year than they used to win in two.

Cleveland is 19th. Oklahoma City, despite the presence of Westbrook dishing dimes, is 26th. Six of the top 13 teams would, if the season ended today, miss the playoffs.

The numbers weren’t any clearer last year. Sure, Golden State was again on top, as they assisted on 68.0 percent of their makes and went 73-9. But five of the top nine teams missed the playoffs. Cleveland, the eventual champions, finished 16th. Toronto was dead last and went 56-26. Only four of the bottom 11 teams missed the playoffs; six of the top 11 did (and in 12th sat Philly, which had the second-worst 82-game season record-wise in the history of the league.)

So hey, guess what? The data tells us that assists are a terrible measure of ball movement, or at least of the kind of ball movement that wins actual basketball games. Seasons in which wins and assist percentage correlate more strongly seem to be outliers rather than defining trends even as you go further back; at least during the pace-and-space era, it doesn’t seem to matter all that much if someone gets the dime as long as the team gets the points.

So what we need is a more comprehensive stat to measure “ball movement” other than assists.

Assist-to-turnover ratio, perhaps? After all, taking care of the ball and not making dumb passes off the basket support or into the third row probably means you’re converting passes into scores efficiently, right?

Nope. Well, not really. Sure, if you turn the ball over excessively, you’re going to suck; 11 of the 16 teams with the worst A/TO ratios have losing records, but only four of the eight best teams in that metric have winning records. That’s kind of a wash.

How about the best players for assist rate, a microcosm of their overall impact, in the league. Are their teams any good?

Well, your top five guys are Westbrook, Harden, Wall, Chris Paul, and LeBron James, in that order, all playoff-bound and with three assured of a first-round home playoff Game 7 and one other (CP3) in position to challenge for the four seed. So far, so good.

But the next five guys are Ricky Rubio, T.J. McConnell, Rajon Rondo, Deron Williams, and Jeff Teague. All five play on teams with losing records (or at least Williams did for the majority of the season before being traded from Dallas to Cleveland); only Rondo’s Bulls and Teague’s Pacers would be playoff teams if the season ended today.

Next four are Dennis Schröder, Jrue Holiday, Sergio Rodriguez, and Elfrid Payton. Nine players between six and 14. Nine guys who played most or all of the season on lousy teams (and Atlanta, since they went into freefall, is a lousy team.)

So can we stop focusing on assists? They create a selfish incentive for players trying to chase stats (Rondo is infamous for “selfish assists”, as Jeff Van Gundy calls them, and Westbrook’s been accused of stat-padding as well in pursuit of his Big O season), and unless your offense is based around pinging the ball around like a pinball to get the best shot (which Steve Kerr has mastered in Oakland), they don’t help you win.

So let’s stop talking about assists, and put them on the same scrap heap as RBIs and saves in baseball.