basketball

The Ups and Downs of Rookie Shot Making

Adjusting to life in the NBA can be tough on rookies – let’s look back at last year’s class and retrace the highs and lows of their shot making peaks and valleys from year one.

This week, Synergy Sports is introducing a few new metrics to help coaches and scouts develop winning team strategies. The first, Synergy Shot Quality (SSQ), uses the contextual information we collect about every play to determine the probability a league-average shooter makes a shot in the same situation (you can read the SSQ explainer for more info on how it works). SSQ is a generic measure of shot quality, a baseline against which to compare shooting performance. The complementary metric Synergy Shot Making (SSM) tells us how much an individual shooter exceeded expectations relative to a league-average shooter facing the same situation. SSM is a measure of shooting skill that accounts for the difficulty of a player’s shot mix.

When a player enters the NBA, three things tend to happen:

  1. His shot quality increases (in part because most rookies are asked to “do less” than they did in college but also because the league average shooter is better in the NBA than in college, so expectations are higher for the same shot mix).
  2. His point-per-shot average tends to decrease, and as a consequence of the first two things.
  3. Nearly every rookie experiences a dip in shot making numbers after entering the league. This SSM drop-off is apparent in this year’s rookie class as well.

Among the rookies who have taken the most shots so far this year (at least 125), the typical increase in SSQ from last year to this year was an additional +0.06 expected points per shot, the typical decrease in PPS was -0.12 points per shot, and as a result the SSM for all but two players decreased (median of -0.19 fewer points above expectation per shot). But what can we expect for the rest of the season? How quickly do rookies tend to adjust to life in the NBA? And how will these shot making numbers look at the end of the year? We can look at the shot making ups and downs for last season’s rookies to get a sense for the most likely outcomes.

Last season as a rookie, Bones Hyland experienced the type of best-case-scenario shot making improvement about which every GM, coach, and scout dreams. Like most rooks, he started the season with minus shot making, that is, his point-per-shot average (the black line in the chart below) wasn’t keeping up with what we would expect to see from a league average shooter facing the same situations (his shot quality, the gray line in the chart). The deficit between his PPS and his SSQ (the blue area) translates to a negative SSM, which means he started the year with below-average shot making. As the season progressed, Hyland’s shooting percentages improved, and he finished the year with a huge, red spike in shot making (positive SSM). This is what everyone is hoping to see for their young players – they get comfortable with the speed of the game, things slow down, and their performance (their shooting, specifically, in this case) improves.

In Hyland’s chart, the jump in PPS (the black line) is so dramatic that it is easy to overlook the importance of the relatively subtle decrease in SSQ (the gray line). Over the course of the season, the Nuggets relied on Hyland to carry a heavier offensive load, as he took on more ball handling and was responsible for creating more of his own looks. The larger role translated to a more challenging shot mix which is what caused the gray line to go down (from a peak SSQ of 1.07 expected points per shot down to a minimum of 0.99). The fact that Hyland was able to remain productive while taking on a more difficult shot diet gave the Nuggets faith that he could continue to play a central role in their offense going forward. Denver’s confidence in Hyland is presumably part of the reason they felt comfortable trading point guard Monte Morris (and Will Barton) to Washington after the season ended.

Hyland’s shot making chart is an extreme example of a pattern that was shared by several other rookies last season, including Jalen Green, Scottie Barnes, Josh Giddey, and Tre Mann.

Obviously, the switch from blue (minus shot making) to red (plus shot making) is more subtle in these four charts than it was in Hyland’s but the theme is the same. These rookies began the year with big blue valleys of below-average shooting but finished the year with small red peaks of above-average shooting. That’s a really promising sign of development for a group of players who were each only 19 or 20 years old last year.

We spotted a substantial change in average shot quality in Hyland’s chart above, but the SSQ dip in Franz Wagner’s chart is even more striking! Look at that gray line go from high (as high as 1.16 expected points per shot) to low (as low as 1.00) and back up again like a roller coaster.

Orlando’s ball handling corps of Cole Anthony, Jalen Suggs, and Markelle Fultz was wiped out by injuries during Wagner’s rookie campaign forcing him to take a more central role in the offense during the middle of the season. That change in role caused his shot quality to temporarily decrease because he was forced to create more of his own shots as the pick-and-roll ball handler and in isolation. We can use the game breakdown feature from the shot type tab of Wagner’s player page on the Synergy team site to visualize how his shot mix changed with his added responsibilities.

In the top table, we see a stretch of four games in February that Wagner played alongside Anthony and Suggs in a secondary offensive role. During this ‘healthy teammates’ period of the season, he took 11 shots per game, 3 of which were catch-and-shoot and 4 of which were created as the ball handler in PNR or in isolation. By our estimation, only one of the 45 shots Wagner took during these four games was characterized as a “low SSQ” attempt. We set the threshold for low shot quality at the 20th percentile for the league or, in other words, a shot with an expected value less than 4 out of every 5 shots taken around the NBA (SSQ < 0.86 expected points per shot in this case). On the other hand, 17 of Wagner’s 45 shots during these four games were “high SSQ” attempts (above the 80th percentile SSQ threshold of 1.25 expected points per shot, higher quality than 4 out of every 5 shots taken around the league).

In stark contrast, the bottom table shows a stretch of four games in December during which Anthony and Suggs (and Fultz) were hurt and, consequently, Wagner played a more central role in the offense. During this ‘injured teammates’ period of the season, Wagner took 19 shots per game, only 1 of which was catch-and-shoot and 10 of which were created as the ball handler in PNR or in isolation each game. We calculated that 16 of the 77 shots he took during these four games were low SSQ attempts and only 5 were high SSQ shots.

Understanding the context of Wagner’s changing role and shot mix over the course of his rookie year is critical to evaluating his development. After an initial rookie slump (the biggest blue valley) at the start of the year, Wagner’s shot making pretty much tracked with his shot quality (ie. the black line bounced around the gray line that went down and back up again). Without proper context, Wagner’s shooting percentages would appear inconsistent but – considering the changes in his shot quality – his shot making was actually consistent throughout the year.

Another player who found himself in a similar situation was Pacers rookie, Chris Duarte.

 

Like Wagner, Duarte’s gray line (his SSQ) went up and down (and up and down again) over the course of his debut season. And, like Wagner, Duarte’s team dealt with absences of key ball handlers. Indiana’s Malcolm Brogdon was in-and-out of the lineup all year with injuries and then a few trades at the end of the season reshuffled roles once again. As a result, there were periods of the season where Duarte was playing more on-the-ball and periods of the season where he was playing more of a secondary role. Again, we can see how his shot mix changed from game-to-game using the game breakdown feature from the shot type tab of Duarte’s player page on the Synergy team site.

 

The top table shows three games that Duarte played alongside Brogdon. He took 8 shots per game and none of them were low SSQ attempts. The bottom tables shows three games later in the year during which Brogdon was out. Duarte doubled his attempts to 15 per game and all of that additional usage came in the form of medium- or low-SSQ shots. Again, you can see how – even though Duarte’s PPS (the black line) goes up and down over the course of the season – his shot making is relatively stable (no big blue valleys or big red peaks). You can contrast Duarte’s chart with that of Davion Mitchell who had a relatively flat gray line (consistent shot quality) with lots of blue and red on either side (periods of plus- and minus-shot making during the year.

It’s worth noting that – even in Mitchell’s extremely up-and-down shot making chart – we see more blue valleys at the beginning of the year (on the left) and more red peaks at the end of the year (on the right), which is probably a positive sign for his development as a shooter.

Obviously, not every rookie is going to have a shot making chart that makes him look like a rags-to-riches development story. The Bulls’ Ayo Dosunmu got off to a scorching hot start to his first NBA season – hitting 40 of his first 100 3-point attempts. He came back to earth eventually (making “only” 30 of his next 86 3PA, 35%), but, overall, it was some impressive shooting for a rookie with lots of red peaks (plus shot making).

If Dosunmu had the reddest shot making chart of any of the high-volume rookies, these four had the bluest ones.

You’ll notice that Evan Mobley, Alperen Sengun, and Herb Jones were all posting scoring rates of more than 1 point per shot for long stretches of the season (black lines above 1.0) but they were mostly unable to match the even higher expectations set by their shot diets (minus shot making, in blue). Mobley and Sengun closed the season with a similar pattern – each attempted increasingly higher quality looks with increasingly higher scoring rates. It’s worth remembering that players like these “deserve some of the credit” for the easy shots they are taking because they are helping to create those shots with effective cuts and rolls and by bullying defenders in the post.

Using the player minutes tab on the Synergy team site, coaches and scouts will be able to track changes in SSQ and SSM from game to game or over time. Which of your players are slumping? And what’s changed? Is it a tougher shot diet or something else? SSQ and SSM metrics will let you spot shooting trends like these and help you investigate what’s causing them. Check it out and let us know what you think.

 


 

Todd is building tools to help coaches, scouts, and players find winning team strategies as part of Synergy’s Analytics and Insights Team. He creates inviting infographics, engaging charts and interactive displays that make data compelling and accessible. Follow him on Twitter @crumpledjumper

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