Last night, the Miami Heat rallied from an 11-point deficit entering the fourth quarter to defeat the Milwaukee Bucks 119-114. That got me thinking: What was the greatest comeback in NBA postseason history?
I don’t have play-by-play data for games earlier than the 1997 NBA Playoffs, so I can’t necessarily find the largest deficit a team has overcome in a given game. However, I do have scoring by quarter for every playoff game in NBA history, so I used data from the 1980 NBA Playoffs — the first year the 3-point shot was used — through the 2022 NBA Playoffs* to build models to predict the home team’s win probability after each of the first three quarters.
* I omitted the 2020 NBA Playoffs when building these models, as there were no true home games in the Walt Disney World bubble.
Here are the results of those models, where “homeDiff” stands for the home team’s point differential at the end of each quarter:
z1 = 0.495935 + 0.107364 * homeDiffz2 = 0.390267 + 0.145429 * homeDiffz3 = 0.288885 + 0.212477 * homeDiff
The logits (“z”) can then be used to estimate the home team win’s probability:
Using last night’s Bucks-Heat game as an example, the probability that a home team trailing by 11 points after three quarters will win the game is:
In other words, we would estimate the Heat had an 11.42% chance of winning last night’s game entering the fourth quarter. The away team’s win probability is just the complement of the above:
Using this method, here are the five biggest playoff comebacks from 1980 to present:
Los Angeles Clippers at Memphis Grizzlies (April 29, 2012)
Clippers down by 21 points through three quarters
Probability = 0.0086Golden State Warriors at New Orleans Pelicans (April 23, 2015)
Warriors down by 20 points through three quarters
Probability = 0.0106Boston Celtics vs. New Jersey Nets (May 25, 2002)
Celtics down by 21 points through three quarters
Probability = 0.0152Phoenix Suns at Houston Rockets (May 11, 1994)
Suns down by 18 points through three quarters
Probability = 0.0161Atlanta Hawks at Philadelphia 76ers (June 16, 2021)
Hawks down by 18 through three quarters
Probability = 0.0161
As you can see, 11 years ago the Los Angeles Clippers had the greatest playoff comeback of the 3-point era (at least by this method), rallying from a 21-point deficit after three quarters to defeat the Memphis Grizzlies.
While I was at it, I decided I might as well build models for the era beginning with the introduction of the shot clock (1955) and ending with the last season before the adoption of the 3-point shot (1979). Here are those results:
z1 = 0.64863 + 0.11903 * homeDiffz2 = 0.53701 + 0.15910 * homeDiffz3 = 0.43091 + 0.25411 * homeDiff
The biggest comebacks of that era are:
New York Knicks vs. Boston Celtics (April 22, 1973)
Knicks down by 16 points through three quarters
Probability = 0.0257San Francisco Warriors at Philadelphia 76ers (April 23, 1967)
Warriors down by 12 points through three quarters
Probability = 0.0299Los Angeles Lakers at Atlanta Hawks (April 12, 1970)
Lakers down by 15 points at halftime
Probability = 0.0510San Francisco Warriors at St. Louis Hawks (April 12, 1967)
Warriors down by 18 points after first quarter
Probability = 0.0578Golden State Warriors at Washington Bullets (May 18, 1975)
Warriors down by 14 points at halftime
Probability = 0.0593New York Knicks at Los Angeles Lakers (April 29, 1970)
Knicks down by 14 points at halftime
Probability = 0.0593
Not surprisingly, comebacks from extreme deficits were less common before the introduction of the 3-point shot. For example, from 1955 through 1979 there were only 21 cases out of 853 playoff games (2.46%) where a team overcame a double-digit halftime deficit to win, but from 1980 through 2022 there were 120 such cases out of 3,231 playoff games (3.71%).
Let me end this post by returning to my original question: What was the greatest comeback in NBA playoff history?
Given the results above, I would have to chose the Clippers incredible 21-point comeback on the road versus the Grizzlies. The play-by-play account is available for that game, and amazingly the Grizzlies held a 24-point lead with less than 8:00 remaining in the fourth quarter. From that point forward, though, the Clippers outscored the Grizzlies 28-3.
That run included a brilliant stretch of shooting by Swaggy P (aka Nick Young), as he nailed three 3-pointers in a 60-second span to trim a 12-point deficit to just three points. Chris Paul hit two free throws with 23.7 seconds remaining in the final period to put the Clippers up 99-98, their first and only lead of the game.
Love this stuff. Thank you!