So Close: What Are the Odds of Making it A Game#

April 18, 2025

What Are The Odds The Game Will Get Close?#

Somebody on reddit posed this question:

Was having a pointless debate with my brother after the 1st quarter of the Brooklyn v Cleveland play-in game. I told him that the game wasn’t over yet, but not because Brooklyn isn’t better than the Cavs. I said it wasn’t over because 20 point leads in the first quarter are a myth in the NBA. I suggested that more often than not (unless the matchup is extremely uneven), teams come back from 20 points down to make it a close game. What are your thoughts on this? I couldn’t necessarily find stats to back my claims up, so I figured reddit might have some strong opinions haha.

And I realized that a quick modification to what classifies as ‘win’ and I could more fully answer this question:

So if you’re down 20 after the first, historical game data suggests you have:

  • An 8.8% chance of coming back and winning

  • A 15.5% chance of tying the game at some point and

  • A 34.5% chance of pulling within five.

So a third of the time, you get a pretty close game, but not “more often than not”. And just to note, this 2022 Cleveland play-in game did get down to within 5 albeit in the last 20 seconds.

However, the entire situation is rare: out of the ~36,000 games since 1996, only 149 teams have fallen down exactly 20 points after the first quarter and of those only 52 have pulled within 5 or less over the game.

As time winds on, a similar pattern maintains. At the half you get:

And at the start of the 4th quarter you get:

Modern Era#

Above, I looked at this for all games since 1996, but it doesn’t change much if you limit it to the last 8 years and draws the same conclusions:

What Are The Odds A Beaten Down Team Will Repay The Favor?#

And, just because it was easy, we can also look at some games with huge point swings:

Which points out that on 11/01/2015 Miami was down 19 to Houston at the half, tied it up by the 4th and went on a late 4th quarter rampage and went up 22 points and finally won 89-109. Rare.

Note, I just did a quick local modification on a branch to the codebase to generate these plots. So some UI elements might say Win % where it means Occurs %. Also, this is not integrated into the interactive dashboard.