Sticky Summer (League) Stats

What you should and should not take away from summer league

It’s almost cliché at this point to say don’t take what you see in summer league too seriously. Players can stand out in a couple of meaningless exhibition games and then never be heard from again. For the most part, it’s tough to know what (if anything) will translate to a player’s rookie season.

To see what might have a good chance of carrying over I took a look at the last ten years of summer league data and matched it up with each player’s rookie season stats. The goal was to find sticky stats — ones that tend to correlate strongly between a player’s summer league debut and their rookie season.

The chart below shows 15 different box score stats for players that logged at least 50 minutes in their first Summer League and 250 minutes in their rookie year. The stats, which are expressed mostly on a per 36 minutes basis, are ordered from most to least correlated.

The charts in the bottom right hand corner of the graphic are some of the least correlated stats. Things like summer league three point percentage and free throw percentage, which are heavily volatile under small sample sizes, are hardly at all correlated with a player’s numbers in their rookie season.

Similarly, minutes per game in a player’s Summer League debut and their rookie season has almost no discernible relationship. That’s understandable given that many of the players appearing in summer league are just hoping to nab the 15th spot on a roster.

Meanwhile, in the top left hand corner of the graphic, a player’s three point attempts per 36 minutes in summer league is heavily correlated with their three point attempts per 36 minutes in their rookie season. This make sense. It’s unlikely that a player is suddenly going to develop a confident three point shot in the short time between summer league and their first game. Conversely, unless your name rhymes with Farkelle Multz, you’re probably not going to lose confidence in your shot in such a short period of time either.

The chart below shows the last ten years of data on three point attempts per 36 minutes in summer league and a player’s rookie year. The dotted line represents how many threes per 36 minutes we’d expect a player to attempt in their rookie season based solely on how many they attempted in summer league.

For example, Cade Cunningham took a little more than 11 threes per 36 in summer league, so a reasonable guess is that he’ll attempt about eight threes per 36 in his rookie season. That’s just a touch under the number that his teammate Saddiq Bey averaged last season when he set the record for three points attempts per 36 minutes by a rookie.

The other stat that is especially sticky is assists per 36 minutes. Again, on an intuitive level, this makes sense because it’s capturing a player’s style more so than their production. Creating for others is partially a mindset. Someone who is regularly looking for their own shot is not suddenly going to rewire their brain in order to get other players involved. It might happen over time, but don’t expect it to happen in a player’s first year.

The chart below shows the last ten years of data on assists per 36 in summer league and in a player’s rookie year. Once again the dotted line is the expected value based solely on how many assists they averaged per 36 minutes in summer league. Here, a player like Cunningham is expected to average around three assists per 36 minutes his rookie season. For reference, that’s about the same amount that Collin Sexton averaged his rookie year. In other words, don’t be surprised if Cunningham isn’t a flashy passer right out of the box.

One guy whose exceptional play in summer league I think has a good chance to translate to his rookie year is Bones Hyland of the Denver Nuggets. Hyland launched nearly 11 threes per 36 minutes in summer league — good enough for fifth most among all rookies that logged at least 50 minutes in summer league. Meanwhile, he averaged a more than respectable six assists per 36 minutes as the Nugget’s lead playmaker. That’s a good sign for someone whose draft profile suggested he was more of a score first type of guard.

Given that Hyland might be Denver’s best three-point threat and passer in the backcourt until Jamal Murray returns from injury I am intrigued to see his Rookie of the Year odds are currently at +8000 on the Action Network.

The only thing stopping me from dropping all of The F5’s annual revenue on those odds is the fact that his head coach is Michael Malone. With the exception of Jamal Murray and Emmanuel Mudiay, both lottery picks, Malone has historically dolled out few minutes to his rookies. Given that Hyland was a late first round pick I’m not getting my hopes up that Malone will make any kind of exception this year.