Analyzing ATS and O/U Data for the NBA Play-In Tournament

by Team Del Genio

We at Team Del Genio like to assess the against the spread and totals data for unique circumstances where perhaps the situation presents an inherent edge to the favorite/underdog or over/under that the oddsmakers and/or market may fail to appreciate. Last month, we looked at how NCAA tournament teams performed in their next if they won their previous tournament game in overtime. This time, we examine NBA play-in tournament games. 

The play-in tournament to qualify for the quarterfinals of the Eastern and Western Conference playoffs is not like any other playoff game in the NBA. While there is a single-elimination dynamic for most of the teams competing in this event (with the exception being for the initial seventh and eighth seeds who earned the opportunity to play a second play-in single-elimination game for the eighth seed if they lose their initial play-in game for the seventh seed), those games are different than elimination games in seven-game playoff series. A playoff series where teams play each other four to seven times in a row breeds familiarity and rewards adaptions and adjustments. These play-in games lack that component. These games might produce interesting data that comes from (relatively) unfamiliar opponents playing in must-win showdowns. 

The NBA has now had three play-in tournaments, yet for our purposes, we are going to ignore the data from its initial incarnation since those games were played on a neutral court in the bubble during the pandemic-impacted 2020 season. Last year was the first time play-in games were played on true home courts with fans. All six home teams were favored, yet only three of them covered the point spread in victory. Four of the home teams won their games, with Memphis’ 100-96 victory against San Antonio as a 4.5-point favorite being the lone game where the home team won straight-up but did not cover the point spread. The over/unders split out at 3-3, yet the final game went over only because Memphis’ upset win against Golden State went to overtime. That game was still 18 points under the number before the five-minute overtime session where 31 combined points were scored.

This year, all six play-in games finished under the number. Atlanta’s initial 132-103 victory at home against Charlotte to advance to play for the eighth seed was the closest call with that final score just finishing under the common closing number of 235.5. All five remaining play-in games averaged more than 11 points below the closing total. The under holds a 9-3 edge in the twelve play-tournament games played on a true home court. 

All six favorites in the play-in tournament this year won their games. Five of these six favorites covered the point spread in their straight-up victory. Two of these favorites were on the road. Both of these road favorites were playing in the final play-in game, and both covered the point spread in their straight-up victory. In the last two years of play-in games not taking place on neutral courts, favorites are now 8-4 ats. Home teams are just 6-6 ats.

Favorites and unders may have had past underlying value in the NBA play-in tournament. 

Good luck - TDG.

All photographic images used for editorial content have been licensed from the Associated Press.

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