Best and Worst Passers in the NBA - 2017/2018

Ben Simmons

Chris Paul. James Harden. LeBron James. Rajon Rondo.

It’s tough deciding on who the best passers in the NBA are - everyone’s preferences are different, and there’s basically an option for everything. Love full court outlet passes? Kevin Love’s your man. Laser-like kickouts for three? John Wall is happy to show you what he’s got. With so many different aspects of the basketball becoming more science than art, it’s refreshing to watch the NBA’s best passers work their magic in their own particular ways.

After spending a few hours sucked into the highlight-vacuum that is YouTube, I started thinking about how we might be able to measure who the best passers in the NBA are - quantitatively. Sure, Lonzo Ball throws some fancy passes. But everybody looks good in their highlights! The real question at hand: does he make his teammates better? I set off to find out.

Measuring the Best Passers

To measure the best passers in the league, I knew I couldn’t use a simple statistic like gross assists or assist percentage, which are influenced so heavily by situational factors such as team, role, and lineups. Instead, I needed to create a statistic that measures how much better, on average, a given player’s passes made his teammates. With this information, we would have a way of comparing the effectiveness of a given player’s passes while controlling for his team and teammates.

To solve this problem, I leveraged the NBA’s advanced passing statistics, which records both assists and potential assists. Potential assists are exactly what they sound like - passes that lead to shot opportunities. However, they are not sensitive to whether or not the player made the shot, like assists are.

The first step in my process was creating a ratio between assists and potential assists for each player - a representation of how often a player’s potential assist opportunities are actually turned into points. A high value for this statistic (which I’m calling Assist Conversion Rate) is indicative of a player’s teammates converting assist opportunities into points at a very high rate - something that would happen if the player was throwing great alley-oop passes, finding men for open three-pointers, and the like. Conversely, a low value for this statistic implies that the passer is putting his teammates in low-percentage scoring opportunities, where the teammate is less likely to score a basket.

Assist Conversion Rate = Assists / Potential Assists

Now, you’re probably thinking “Conor, this all sounds good. But what about teams who are worse at shooting across the board? Won’t this make certain players look worse by this metric, just because their teammates are less likely to make the shots, even on great passes?” To resolve this issue, I went back to the data and controlled the new Assist Conversion Rate by each team’s overall shooting percentages, so that the quality of one’s teammates doesn’t skew the passing numbers.

The output of this step is another new statistic I’m calling Assist Conversion Difference - designed to show how much better or worse than average a player’s teammates shoot off their passes in particular, compared to the team-wide shooting percentage. A value of zero implies that a given player’s passes lead to shots made at a team-average rate, while a positive number implies that a given player’s passes lead to shots made more often than we would expect, given the team they play for (with the negative fitting accordingly). Basically, big number -> easier looks. Small number -> harder looks.

Assist Conversion Difference = Assist Conversion Rate - Team Shooting %

The Results

It’s most interesting to look at the two ends of this data, which is filtered to focus on players who averaged 5 assists or more per game over the course of the 2017-2018 regular season. While all of the values are positive (makes sense - you don’t want a terrible passer handling a significant playmaking role on your team), there is a wide spread in values, and some surprising characters at the top and bottom.

At the top, with his teammates shooting over 17% better on his passes, is Nikola Jokic, a big man on the Nuggets known for doing insane things like this:

Jokic has been regarded as one of the NBA’s best interior passers since entering the league, and his ability to hit cutters and shooters while covered or even double-covered is no doubt the reason why he scores so highly by this metric. The attention defenses pay Jokic opens the lane for a lot of high-quality looks for his teammates, and Jokic is more than able to make them pay.

The opposite end of the chart is more difficult to reconcile, with Rookie of the Year Ben Simmons coming in last. Despite Simmon’s clearly outrageous passing abilities, his teammates shot only 0.75% better on passes from him over the course of the season. Now, it’s important to recognize that this is just one statistic, which doesn’t change the fact that Simmons is a prodigiously gifted player. It does mean, however, that he still has plenty of work to put in to get on the level of other play-making forwards around the league, and demonstrate that his passes lead not only to highlights, but to points.