The Science of Heat Checks

Using our new Synergy Shot Quality model to quantify how NBA players tend to react to hot (and cold) streaks.

Jordan Poole is having a coming out party this postseason. Thrust into the starting lineup by an injury to his teammate, Steph Curry, Poole played well enough in the first four games of the Warriors first round matchup with the Nuggets to keep his starting spot for the foreseeable future (despite Curry’s return to the lineup in Game 5). And, frankly, Poole is just playing too dang good right now for coach Steve Kerr to leave him on the bench for any sustained period of time. His emergence as a dangerous and increasingly *consistent* third scoring threat in the series – chipping in 21 points per game on 48% shooting from three – has the Warriors looking like championship contenders once again.

Poole’s scoring outburst hasn’t come as a complete surprise – he’s been contributing at a high level all year – but it has been impressive to see the confidence this 22-year-old is displaying in his first trip to the postseason. He was in attack mode right from the jump against the Nuggets, using his quick first step and dead eye shooting to score in bunches. In fact, he made each of his first six field goal attempts in his playoff debut, finishing the first half with 17 points.

But there is a fine line between confidence and overconfidence. And Poole followed up his scintillating first half debut with this high degree-of-difficulty, half-spin hesitation move into a step-back, 27-foot three-point attempt.

If we look back at Poole’s shot sequence from the second quarter of Game 1, we can see how he ratcheted up the difficulty level of his shots with each successive make. He got things rolling with a pretty vanilla combo of a midrange jumper followed by a driving layup but then he quickly spiced things up by adding in more complicated and challenging shot elements.

This phenomenon – of players following a run of made baskets with increasingly more difficult shots – is sometimes referred to as a “heat check” because the shooter is figuratively asking himself: “how hot am I?”.

I was curious to see if we could find evidence of heat checking among other NBA players and whether we could quantify the typical change in shot difficulty that occurs after runs of hot shooting. Using our new Synergy Shot Quality (SSQ) model, I examined the expected field goal percentage (xFG) of each shot that was attempted during a regular season game over the last five NBA seasons (SSQ and xFG are related, ie. SSQ = xFG * shot value).

I looked at individual shot logs from single games to find sequences of hot and cold shooting. Specifically, I focused on shots that followed three or more consecutive makes (my definition of a hot streak) or three or more consecutive misses (a cold streak). My hypothesis was that players who were prone to heat checking would take more difficult shots after three straight makes than they would after three straight misses. In other words, I wanted to see if the average shooter’s xFG would be lower on shots that followed three makes than it was on shots that followed three misses.

The short answer is yes! Players tend to attempt more difficult shots after a run of hot shooting than they would after a run of cold shooting, at least according to our SSQ model. If we break down the factors that help the model determine shot quality/difficulty we can see how these factors relate to a typical heat check.

The most important factor in determining the difficulty of a shot is obviously the shooter’s distance from the hoop. And watching a hot shooter hoist deeper and deeper shots is certainly a hallmark of the heat check. The average player shot from two feet further away from the basket following three straight makes than he did after missing three shots in a row.

Defensive pressure is tightly linked to shot difficulty as well. Contested shots are harder to make than open ones and the average shooter is more likely to take a guarded jumper after a run of hot shooting than he is to take one after a cold spell. Comparing contested jumper rates after three makes vs. rates after three misses, we see a 4-percentage point higher mark when players are heat checking.

In part, the change in contested jumper rate is a reflection of a hot shooter’s willingness to attempt a more difficult shot; at the same time, it may also reflect how a defender reacts to his opponent’s hot streak. If he feels an opponent is heating up, a defender may close out more aggressively to contest his shots. In their working paper, “Hot Shots: An Analysis of the ‘Hot Hand’ in NBA Field Goal and Free Throw Shooting”, Robert Lantis and Erik Nesson showed that – not only did defender distances diminish in response to hot streaks – but there were also noticeable changes in team defensive strategies. After runs of hot shooting, the coach of the opposing team was more likely to assign a new defender to cover the shooter, more likely to make a substitution, and more likely to call a time out.

We can infer more information about the presence of defenders using the data we collect on shot type and play type. Shots created in isolation tend to be more difficult because – by definition – they require the shooter to beat his defender (and sometimes a help defender as well). In general, one thing that tends to make shooting off the dribble more difficult than catching and shooting is that there is almost always a defender in the way. These shot factors also tend to change when a shooter is heat checking. The average shooter is more likely to take a shot in isolation after a series of makes than he is to do so after a series of misses. Likewise, he is more likely to attempt a pull-up jumper after a run of hot shooting.

The higher rate of iso- and pull-up jump shooting is another clue that a player may push beyond the limits of his normal shot mix to try more difficult shots if he is feeling hot. Likewise, Lantis and Nesson found that a hot shooter was more likely to take his team’s next shot than a cold shooter and that he tended to allow less time to elapse before he took his next attempt after a run of makes. One could interpret these strategic changes as an effort to “feed the hot hand” (especially when additional made shots follow) but the same behavior could also be considered “forcing it” (when it results in subsequent missed shots).

Now, add all these factors up – the longer shot distances, the increased defensive pressure, and the propensity to shoot more in isolation/off the dribble – and what you find is a two percentage point drop in xFG after three makes (relative to xFG for the same player after 3+ misses). Here are the 20 NBA players who have had the biggest drop-offs in xFG following runs of hot shooting over the last five years, these are the heat-checking-est heat checkers in the league.

Obviously, not everybody is afforded the opportunity to heat check. Players with very prescribed shot diets (think: Clint Capela, for example) aren’t given much license with their range of shot difficulty – so they don’t get a chance to heat check very often. It’s really only the players who have a diverse shot mix (and, more specifically, the ones who take a lot of shots) who have the potential to be the legitimate heat checkers. As a result, many of the players at the top of the list are among the biggest stars in the game – Luka, LeBron, Lillard, Leonard, Lavine – as well as some budding stars like Poole and Anthony Edwards. The list also contains some unrepentant chuckers like Austin Rivers and Kyle Kuzma.

Interestingly, a few teams are overrepresented in the table which may indicate that some coaches have more tolerance to the practice of heat checking than others. Are coaches like Mike Budenholzer (who coaches Portis, Antetokounmpo, and Lopez on the Bucks) and Steve Kerr (who has coached Wiggins, Poole, Russell, and Oubre on the Warriors for stretches of the previous five seasons) more willing to give their hot shooters some leeway to push their own limits? And if that is the case – would that be a good thing or a bad thing?

What should we take away from all this? It’s clear that when NBA players experience a run of hot shooting, they tend to respond by taking more difficult shots than they would otherwise. Sometimes (most of the time?) this is not a productive strategy. So, should coaches be discouraging this type of heat checking? If you were Steve Kerr, would you really want to discourage Jordan Poole from heat checking?

A shooter’s confidence can be a fragile thing. Poole is oozing the stuff right now and he’s putting a ton of pressure on the defense with his willingness to take (and make) difficult shots from all over the court. Sometimes a few bad shots are just the price to be paid for that kind of swagger.

What’s your philosophy on heat checks? What’s the best way to encourage a young player to shoot with confidence without compromising his team’s ability to get good looks



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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