$w.onReady(function () {
top of page

HOW MUCH DOES REST IMPACT NBA GAMES?

Fact or Fiction?


Is the number of days between games a key statistic to look at when betting on NBA games?


Background


NBA bettors’ constantly mention how many days of rest teams have when they discuss which teams to bet on. They believe that extra days off will allow a team to play its best players longer minutes and limit fatigue, giving the team a hlarge boost.


Over the past several seasons, the NBA has made an effort to limit the number of back-to-back games teams play. As recently as the 2014-15 season, 20% of NBA games were back-to-back, while last season, this number fell to 13%. The reasoning behind this is twofold. First, back-to-back games increase the risk of injury. Secondly, fatigue results in poor quality basketball in the second game.


The average NBA record in the second game when teams play on consecutive days shows the clear disadvantage a team faces. Teams win only 42.7% of their second games when they play two in a row. However, these losses are only partly due to fatigue since it has become normal to sit leading players for the second game and because more than half of back-to-back games are played on the road.


Impact of Back-to-Backs


We ran a statistical analysis to see if there was any connection between days off and offensive and defensive output or efficiency. We found that there is no connection between defensive output and days off, however there is a slight to moderate connection between days off and offensive output.


Using back-to-back games as a baseline, we found that offensive output goes up 1.5 points for one day off and 3.3 for two days off. Yet, more than two days off does not result in any further increased output. Consequently, increased offensive output can be understood as the main advantage for NBA teams that are rested.


For context, a day off is roughly equal to just one(!) turnover or a 3% increase in defensive rebounding percentage. So, there is a real, but only moderate impact on game outcomes.


Takeaways


For bettors’, if teams win on the second day of a back-to-back is only part of the story.


The real focus for bettors’ should be how these teams do against the spread. If there is a perception that back-to-backs make a huge difference when they only make a moderate impact, is it possible the sportsbooks have over adjusted the odds for these games?


Over a six season span from 2013-2020, teams on the second day of a back-to-back, won over 50% of their games against the spread. However, this was only 8 games over 500, and so does not reveal an advantage and instead shows that the sportsbooks have already accounted for this disadvantage while making their lines.


An edge in days off can represent a slight to moderate advantage in NBA basketball, yet the sportsbooks have already factored these in, so they do not present a chance for efficient betting. Therefore, when betting these NBA games, note the rest advantage, count its moderate impact, and glean if the sportsbooks have already accounted for this.


Bonus Fact or Fiction


Do back-to-back games lead to different point totals?


It might be logical to think that as teams fatigue, they are likely to slow down the pace of the games, and in turn lower the point totals. Our analysis found that two days off does raise the average pace, but adds less than one possession per team per game.


Further, the results for over-unders are very consistent regardless of how many days off teams have had, with around half going over and half under the point totals.


This is likely because the differential between over under totals for back-to-back games is about one point less than the average point total for games with two days rest (223.3, 224.4), roughly equal to the added possession or two per game.


Takeaway


Back-to-backs do result in very slightly lower scoring games, but this is minimal and has already been factored in by the sportsbooks.


Comentarios


bottom of page