Keldon Johnson and the art of the Spot up

One of the most pleasant surprises of this rebuilding season has been Keldon Johnson’s incredible shooting. Keldon has emerged as one of the most effective outside shooters in the league. Of the 154 players in the league who have taken at least 200 attempts, he is second in the league in accuracy with 43.2%. That’s great news for the 3rd-year player and worthy of a deeper investigation. So get your protractor and your old TI-81 and join me in this installment of the Professor’s Corner as we examine Keldon Johnson and a specific offensive play type: The spot up.

Synergy Sports, via player movement tracking data, categorizes offensive possessions into play types such as pick & roll, isolation, catch & shoot, and several others. The spot up is one of the more diverse categories since it includes the 4 potential (non-pass) outcomes that can occur when a player receives the ball on the perimeter. These include: A no dribble jump shot, dribble to a pull-up jump shot, a runner, and drives to the basket.

Current Spurs players that have a high frequency of spot up possessions are Keldon Johnson and Devin Vassell. Spot up players of Spurs past include Matt Bonner and Bruce Bowen. Players of this genre shoot open shots or relocate themselves to create a shot without the help of a screens. The lack of screen is very important since Synergy has another play type, shockingly named off screens, for they’re involved. The Spurs have excellent examples of both types. Doug McDermott is a prototypical movement shooter that weaves around screens prior to receiving the ball and taking the shot. Keldon Johnson embodies the spot up player.

This chart displays those in the NBA with greater than 150 spot up possessions that have played at least 40 games. Keldon is averaging 5.4 spot up possessions per game and is averaging 6.5 points per game from those possession (resulting in an extremely impressive 1.2 points per possession (PPP)). There are very few players better than Keldon in this play type. As a reference, others who excel as “spot up” shooters are Patty Mills, Norman Powell (5 year $90 million contract—please note for the future), Cameron Johnson, Desmond Bane, and All-Star starter Andrew Wiggins. This is solid company, but what is very impressive is that it’s actually Keldon Johnson that is leading the league in the total points scored in spot up possessions!(1)

How did we get here?

Yes, you read that correctly. I’m willing to guess that most following the NBA, including Spurs fans, would be very surprised to hear that Keldon Johnson leads the league in scoring in spot up possessions. One of the major reasons for this surprise is the recency. Literally, it just happened. Last season Keldon was a low volume, moderately accurate outside shooter that was more known for his head down, starkly void of passes, drives to the rim. But wow, per the chart below, times have changed!

The chart below displays Keldon’s 3-pt attempts (in “cooler” colors) and accuracy (“warmer” colors) since the start of his career (rolling 5-game average). You can see that at -95 game mark there begins a meteoric climb upwards in the attempts per game from 2.5 attempts to >7.0 attempts currently (blue line).

A substantial increase in volume is what I term a “stress test” and it’s clear Keldon passed. After his initial early-season slump, he gradually rose to nearly tripling his 3-point attempts per game while maintaining a 5-game rolling average accuracy ranging from an atomic 54% to a strong 38% (league average is ~35.5%). Thus, Keldon was provided more shots and he become more comfortable and accurate with the increased volume. It’s important to understand that the trend displayed on this chart is way beyond normal. Most shooters fail the “stress test” and shoot substantially worse when provided a considerable increase in volume. In contrast, these data suggest that Keldon is capable of shooting ~6 shots from behind the arc per game while remaining above league average in accuracy. NBA teams pay a lot of money to obtain players with this skill set and the Spurs were able to develop one right in their back yard.

Once section of the chart above is a pie chart that divides Keldon’s spot up possessions into their respective play type distributions and it’s clear that Keldon’s spot up feast is centered around the entre’ of the no dribble jumper. Patty Mills and Keldon sit atop the league in points per possession in spot up shots that don’t involve a relocation via a dribble. Furthermore, when accounting for the value of 3 pointers, Johnson & Johnson (Keldon and Cameron) lead the league in Synergy’s 3-point adjusted shooting percentage. In fact, via total points, only five players have scored more and all those employ no-dribble shots for over 75% of their spot up attempts—meaning, that’s the primary thing they do. In contrast, Keldon’s distribution involves 53% stationary shots and the rest of his spot ups involve him putting the ball on the floor and creating a better shot via pulls ups, floaters, and drives.

Moving forward: Outside shooting across the league.

To see the bigger picture this scatterplot displays moderate to high volume 3-pt shooters across the league. There are currently ~110 NBA players that average >4 3-pt attempts per game and have played in 40 games (this plot shows the top 70 in win shares). The Spurs have 5 of those 110 players: Keldon, Doug McDermott, Devin Vassell, Dejounte Murray, and Lonnie Walker (unfortunately, 3 of those 5 shoot BELOW league average). The Spurs lead the league for having the most players in this group of 110 and this can be attributed to having few high-volume shooters. Doug McDermott averages the most attempts per game (5.3). That seems like a lot for anybody old enough to remember Robert Horry playing for the Spurs, but please consider that Fred VanVleet takes more 3-pt shots per game (~10.0) than Keldon Johnson and Devin Vassell COMBINED. Having several moderate volume shooters is the best approach for a developing team like San Antonio, but a team further down the development road might take a different approach.

Launch More?

When a player hit’s 40% of his 6 long-range attempts per game it’s tempting to hope for more. But it’s obviously not that simple or Tony Snell and Steve Novak would be heading to the Hall of Fame. There are a limited number of open shots in a game. Currently, only 6% of Keldon’s 3-pt shots (15 of 240) have been “tightly” contested—thus, 94% are open shots. This means Keldon is doing exactly what he should—he’s taking open shots that arrive through the flow of a game and hitting a very high percentage of them. Other players must attack this differently. For example, 19% of Doug McDermott’s 3-pt shots (42 of 216) are tightly contested. McDermott is a classic movement shooter. He’s constantly weaving, using screens, and relocating to get shots. Could Doug skip all that scampering about and take open shots? Sure, but there would less for others and that wouldn’t be good for the Spurs.

Movement shooting is a premium skill in the NBA. Movement shooters are the tough shot takers of the team. They use the dynamics of themselves and others to create open/easier shots for their teammates. Therefore, spot up shooters (specifically, with no movement) find the open areas on the court created by the gravity of others. Spurs get open spot up opportunities when players like Dejounte, Jakob, and Doug force defenses to shift. Therefore, Keldon uses others to generate his open shots. And to give you the specifics you’ve come to expect from the Professor’s Corner: Keldon averages 62.5 offensive possessions per game and has averaged ~4.5 open 3-pt attempts over the last 20 games. It is possible that he could increase to 6 attempts per game, but that would likely take open shots away from teammates.

Good Days Ahead

Excluding passes, there are 4 ways a spot up possession ends. (I’ve included Keldon’s frequency percentages) (2)

1. No movement shot (53.6%)
2. Dribble/relocation shot (8.3%)
3. Runner (11.5%)
4. Drives to the basket. (23.0%)

A very positive aspect of Keldon’s game is that he’s not reliant primarily upon number 1. Thus, options 2 – 4 are on the table since he’s able to put the ball on the floor. Considering that Keldon uses option 1 ~50% of the time, defenders MUST approach him like he’s a threat to either drive OR shoot. Contrast this with players like Reggie Bullock and Lonzo Ball in which >75% of their spot up possessions end with no dribble shots. With Keldon putting it on the floor in 50% of his spot opportunities that forces hesitation into the minds of the defenders and giving Keldon more autonomy.

It’s a make of miss league and Keldon can apparently make his. In the last 40 games he’s exploded onto the scene as a player capable of shooting accurately at a high volume. I anticipate that Keldon’s accuracy will decline slightly over the next season as the scouting reports evolve across the league. This will be good for the Spurs. Defenders will be forced to “stay home” on Keldon and this will open up other areas for his teammates. Us Spurs fans love to brag of how the organization excels at developing its talent. Well Folks, via data visualization, this is an exact example of what that looks like.

Notes

1. Keldon is 4^th in attempted spot up shots (244). Lou Dort leads the league with 266 spot up shots
2. ~4% of Keldon’s spot up possessions are turnovers/fouls