NBA playoff travel impacts game outcomes

The direction and magnitude of a team’s traveling during the National Basketball Association’s playoff tournament can impact its chances of winning, according to research presented at SLEEP 2020.

“A great deal of prior work has examined the effects of travel and circadian advantages on team performance during the regular season of various professional sports leagues,” Sean Pradhan, PhD, assistant professor of sports management and business analytics in the School of Business Administration at Menlo College in Atherton, California, said in a press release. “The current study extends such findings of previous research by examining team performance in the NBA playoffs, which is obviously an extremely crucial time for teams competing.”

The findings were initially published in Sleep, the journal of the Sleep Research Society, in May.

Pradhan and colleagues conducted their study to evaluate whether travel affected game outcomes during the NBA playoffs, which adapted a 7-game playoff where teams alternate home and away games 2-2-1-1-1 in 2013.

They assessed the impact of time zones traveled and direction of travel — eastward, westward or within the same time zone — on playoff game outcomes from the 2013-2014 season through the 2018-2019 season.

Researchers used two databases to collect information on 499 postseason games held during the study period.

Pradhan and colleagues determined that teams traveling 3 hours westward had lower probabilities of winning compared with those traveling within the same time zone or traveling eastward. In comparison, teams traveling eastward for 3 hours before a playoff game had higher odds of winning compared with those traveling in the same time zone and all travel westward.

The researchers also found that teams traveling west with 2-hour time changes had significantly more losses than those traveling west who only experienced a 1-hour time change (OR = 2.46), those traveling east with a 1-hour time change (OR = 2.34), and those traveling east with a 3-hour time change (OR = 4.68).

According to the researchers, scores were significantly higher after teams traveled eastward compared with westward travel (P = .001, d = 0.60) and traveling in the same time zone (P = .003, d = 0.44).

Pradhan and colleagues did not identify differences in team quality based on their direction of travel or the number of time zones that were traveled, or on game outcomes based on their overall travel direction.

“During this initial study, it was interesting to find that team scoring improved during general eastward travel compared to westward travel and travel in the same zone, but game outcomes were unaffected by direction of travel during the playoffs,” Pradhan said in the press release. “However, when considering the magnitude of travel across different time zones, we found that teams had predicted probabilities of winning that were lower after traveling three time zones westward, and tended to actually lose more games when traveling two time zones westward compared to most other types of travel.”