Final Part 4: Do NBA Teams Tend To Go Over Or Under At End Of Season?

Today, I want to share with you the continued findings of my research on whether NBA teams tend to go Over or Under at the end of the regular season.

Recently, I noticed a possible pattern in the NBA where teams playing back-to-back games in certain scenarios tend to go Under the total at the end of the season when they are tired.

Last week, I shared with you my findings on the above hypothesis based on the last 10 years of the NBA. But I wasn’t satisfied with just 10 years of data. I needed much more data before coming to any conclusion. In the last week, I continued to dig deeper into the historical stats to discover whether or not there is merit to this betting strategy. Today, I am sharing my latest findings with you in this final part 4 of my research which spans for the last 15 years of the NBA:

Here’s the NBA angle I tested:

• The game must be played on February 1st or after. Reasoning: February is considered a month toward the end of the season where teams tend to start showing fatigue. This affects how many points are scored in the game.
  
• The team must be playing back-to-back games. This means they must play 2 consecutive games without a rest day. Reasoning: At a time near the end of the season when teams are already tired, the fatigue effect is magnified further when a team is forced to play two consecutive games in a row without any day of rest. This can affect how many points are scored in the 2nd game.
  
• Research is now fully conducted and tested for the last 15 years (in parts 1-3, I only tested for the last 10 years)

The hypothesis is that when teams are tired at the end of the season, they tend to slow the pace of the game down and score less points, thus pushing the Total of the game to go Under. Therefore, the smart wager to make is assumed to be on the Under the Total in these scenarios. But is there any truth to this hypothesis?

Here are my findings. Below is the Over/Under the Total record for the last 15 years of NBA (since the 2018 NBA season) on the 2nd game of a back-to-back series starting in February or later:

Overall, more games have indeed gone Under. However, the gap here is not statistically significant enough to conclude any real betting advantage. Furthermore, the key win rate percentage margin to hit is 52.4% in order to break even when betting on sports, assuming all -110 odds. Therefore, there is no betting value to just blindly taking the Under in these situations. Here’s how the record looks for games only start after March or April:

Since no real conclusion can be drawn from the figures above, our hypothesis needs to be further refined through the use of additional filters. First, I want to see what happens if the back-to-back series was played in the order of Home-Home, Home-Road, Road-Home, and Road-Road. The logic behind this is to see if any effects of travel can have a measurable and statistically significant impact on the scoring total of games.

Below are the results of my findings. The records below are written in Over-Under format. For example, Home-Home: 35-45 means that when a team plays two back-to-back home games, the 2nd game goes Over 35 times and Under 45 times:

The home-home combination here yields a winning percentage of 56%. However, the sample size here of just under 150 games may be too small for us to make a conclusion.

I continued to research deeper. What happens if the team lost the previous game, or won the previous game? Would their victory or defeat in the 1st game of a back-to-back series have any noticeable impact on the scoring total of the 2nd game? Here are my findings, again written in the Over-Under format:

This is interesting. The results here indicate that if a team loses the 1st game, they tend to speed up and score more to go Over the Total in the 2nd game, but not at a margin high enough to produce any betting value. On the other hand, when a team wins the first game, they would usually slow down on the 2nd game and go Under the Total at a 53.74% win rate.

I continued to research further. What if the team went Over in the 1st game? What if they went Under? How did that affect their scoring in the 2nd game? Here are the results, again in the Over/Under format:

The numbers are even enough that no betting value can be concluded from these findings. Teams do tend to go Over and Under consecutively, but at no statistically significant amount. However, it is interesting here to note down that when a team goes Over, they tend to repeat it again in the 2nd game. The same is true when a team goes Under: They are likely to repeat that again in the 2nd game as well.

I wanted more. What happened if teams would over-performed or under-performed in the 1st game? Here are the definitions I use for over-performing and under-performing:

Over-perform: The team not only won the 1st game but also won against the spread.

Under-perform: The team not only lost the 1st game but also lost against the spread.

Here are my findings on the Over-Under results in back-to-back series after February if teams would over-perform or under-perform in the 1st game:

The record in the last 15 years shows that if teams over-performed the 1st game (won the game PLUS won ATS), they’d end up going Under 54.7% of the time in the 2nd game! Fatigue issues is the most likely cause here that contribute to this effect.

I still needed more. What happened if teams would over-perform AND also go Over in the 1st game? And what happened if teams would under-perform AND go Under in the 1st game? How did that affect their scoring on the 2nd game of a back-to-back series after February? Here are my findings:

• Teams are more tired later in the season
  
• Teams are more tired playing in the 2nd game of a back-to-back series
  
• Teams that went Under the total in the 1st game mean that they are trending in that direction and are more likely to go Under again in the next game
  
• Teams that overperformed in the 1st game of the back-to-back contribute to further fatigue issues in the 2nd game.

Here is my final conclusion on this betting strategy based on the last 15 years of NBA research:When an NBA team over-performed and also went Under the total in the 1st game of a back-to-back series starting in February, then the smart bet to take is on the Under the total in the 2nd game. This betting strategy has produced a 55.66% win rate within a statistically valid sample size of games in the last 15 years of the NBA.

Click here to see part of my research: Part 1: Do NBA Teams Tend To Go Over Or Under At End Of Season?

Click here to see part of my research: Part 2: Do NBA Teams Tend To Go Over Or Under At End Of Season?

Click here to see part of my research: Part 3: Do NBA Teams Tend To Go Over Or Under At End Of Season?