How 1st-quarter fatigue affects Isaiah Thomas, Russell Westbrook, and James Harden

Last season Isaiah Thomas joined the ranks of elite point guards in the NBA, earning All-NBA second team honors. “The King in the Fourth” became something of a folk hero in Boston. His clutch shooting made it seem like he never got tired, only improving as the game went on. So it might sound strange to focus on his 1st-quarter minutes—but it may be more important than you think.

The idea actually starts with Russell Westbrook. It is well known that the Thunder are generally careful with Russell Westbrook’s minutes. But I’ve also heard people say that 1st-quarter minutes are a specific focus. The idea: if Westbrook was too fatigued from the 1st quarter, his performance would suffer in the rest of the game, regardless of how much he rested after. I wanted to see if there was any statistical support for this, and if it held true for other players like him. This article looks at the three ball-dominant, MVP-candidate guards: Isaiah Thomas, Russell Westbrook, and James Harden.

I separated their 2016-17 games based on the amount of 1st-quarter minutes played. Thomas, Westbrook, and Harden each have distinct 1st-quarter minute distributions. This chart shows the frequency that each guy played a given number of minutes in the 1st quarter.

Thomas has a nice bell curve range, whereas Westbrook is split between nine and ten minutes, and Harden regularly played all 12 minutes.

Next, I calculated their per-36 minutes stats for the rest of the game, after dropping the samples with just one or two games. Those results are in the gallery below.

Grid View

For Westbrook and Thomas, there is a slight decrease in effectiveness that occurs when more 1st-quarter minutes are played. IT’s scoring drops with each additional minute played. His assists also progressively dip as minutes increase, until the 12-minute category.

Westbrook shows a similar drop in scoring from the 9–10 minute samples. It’s hard to ignore the massive spike in scoring for the 11-minute sample, but keep in mind that it includes only 5 games. His rebounding takes a consistent dive, and his assists slightly decrease.

Harden’s numbers are actually better across the board when his 1st-quarter minutes increase.

These are just counting stats, so they aren’t a perfect measure by any means. To help address some concerns about pace, the following graph uses effective field goal percentage instead.

It comes out pretty much the same as the PTS/36 did. Thomas steadily declines, and Westbrook’s drop from 9 to 10 minutes is actually pretty big here. Once again, Harden’s numbers improved when playing more minutes.

On the whole, the numbers for Thomas and Westbrook support this idea that early-game fatigue has an effect on the rest of the game. It’s not huge, but small differences can be important over the course of a season. At the same time, Harden’s numbers cut the opposite way, which is funny because he was noticeably exhausted by his heavy workload by the end of the season. This finding, plus the addition of Chris Paul, may result in Harden’s early minutes more closely resembling those of Westbrook or Thomas.

These data are by no means conclusive. There are plenty of contextual factors at play that aren’t accounted for. I’d also prefer to have possession stats tied to the actual distance tracked by SportVu. But despite these caveats, the idea is still interesting to kick around. With advances in player tracking and training, the way we think about resting players will continue to evolve. Managing early-game fatigue, as opposed to just focusing on total minutes, may just be something we hear more about in the future.