Last night we almost saw two amazing comebacks in the NBA playoffs:
- In Indiana, the Pacers were down by as many as 30 points to the Hawks in the third quarter before a furious rally cut the deficit to nine points with 1:54 remaining. That was as close as the Pacers would get, though, and they eventually lost by 10 points.
- In Dallas, the Spurs led the Mavericks by 20 points in the third quarter but saw that lead dwindle to just one point with 0:19 remaining. San Antonio held on, though, for a four-point victory.
Those games got me thinking: What was the greatest comeback in NBA playoff history?
I don’t have play-by-play data earlier than the 2001 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 almost every game in NBA history, so I used data from the 1980 playoffs — the first year the 3-point shot was used — through the 2013 playoffs to build models to predict the home team’s win probability after each of the first three quarters. Here are the results:
Qtr | Logit |
---|---|
1 | 0.5389056 + 0.1067448 × homeDiff |
2 | 0.4405203 + 0.1501432 × homeDiff |
3 | 0.3297903 + 0.2131430 × homeDiff |
The logit (“z”) can then be used to estimate the home team win’s probability:
p = 1 / (1 + e-z)
For example, last night the Pacers trailed the Hawks by 20 points after three quarters. Thus their estimated win probability was:
p = 1 / (1 + e-(0.3297903 + 0.2131430 × -20)) = 0.0192
Which, of course, makes Atlanta’s win probability:
1 – 0.0192 = 0.9808
Using this method, here are the ten biggest playoff comebacks from 1980 to the present:
Rk | Date | Matchup | Description | WP |
---|---|---|---|---|
1 | 2012-04-29 | LAC at MEM | LAC down 21 after 3rd quarter and won game | 0.0081 |
2 | 1994-05-11 | PHX at HOU | PHX down 18 after 3rd quarter and won game (OT) | 0.0153 |
3 | 2002-05-25 | BOS vs NJN | BOS down 21 after 3rd quarter and won game | 0.0156 |
4 | 2011-04-23 | POR vs DAL | POR down 18 after 3rd quarter and won game | 0.0291 |
5 | 2009-04-19 | PHI at ORL | PHI down 14 after 3rd quarter and won game | 0.0351 |
5 | 2001-05-03 | DAL at UTA | DAL down 14 after 3rd quarter and won game | 0.0351 |
7 | 1986-04-22 | MIL at NJN | MIL down 18 after 2nd quarter and won game | 0.0414 |
7 | 1980-04-27 | LAL at SEA | LAL down 18 after 2nd quarter and won game | 0.0414 |
7 | 1989-05-02 | PHX at DEN | PHX down 18 after 2nd quarter and won game | 0.0414 |
7 | 2008-06-12 | BOS at LAL | BOS down 18 after 2nd quarter and won game | 0.0414 |
As you can see, just two years ago the Clippers had the greatest playoff comeback of the 3-point era, rallying from a 21-point deficit after three quarters to defeat the 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 3-point shot (1979). Here are those results:
Qtr | Logit |
---|---|
1 | 0.6486317 + 0.1190319 × homeDiff |
2 | 0.5370106 + 0.1590951 × homeDiff |
3 | 0.4309060 + 0.2541083 × homeDiff |
And here are the ten greatest comebacks of that era:
Rk | Date | Matchup | Description | WP |
---|---|---|---|---|
1 | 1973-04-22 | NYK vs BOS | NYK down 16 after 3rd quarter and won game (2OT) | 0.0257 |
2 | 1967-04-23 | SFW at PHI | SFW down 12 after 3rd quarter and won game | 0.0299 |
3 | 1970-04-12 | LAL at ATL | LAL down 15 after 2nd quarter and won game | 0.0510 |
4 | 1967-04-12 | SFW at STL | SFW down 18 after 1st quarter and won game | 0.0578 |
5 | 1975-05-18 | GSW at WAS | GSW down 14 after 2nd quarter and won game | 0.0593 |
5 | 1970-04-29 | NYK at LAL | NYK down 14 after 2nd quarter and won game (OT) | 0.0593 |
7 | 1978-05-30 | WAS at SEA | WAS down 9 after 3rd quarter and won game (OT) | 0.0619 |
7 | 1960-03-12 | MIN at DET | MIN down 9 after 3rd quarter and won game | 0.0619 |
9 | 1974-03-30 | BOS vs BUF | BOS down 12 after 3rd quarter and won game | 0.0680 |
10 | 1978-04-28 | MIL at DEN | MIL down 8 after 3rd quarter and won game | 0.0784 |
10 | 1977-04-17 | BOS at PHI | BOS down 8 after 3rd quarter and won game | 0.0784 |
10 | 1974-04-05 | NYK at CAP | NYK down 8 after 3rd quarter and won game (OT) | 0.0784 |
10 | 1967-03-23 | STL at CHI | STL down 8 after 3rd quarter and won game | 0.0784 |
10 | 1979-05-13 | SEA at PHX | SEA down 8 after 3rd quarter and won game | 0.0784 |
Not surprisingly, comebacks from extreme deficits were less common before the introduction of the 3-point shot.
Looking at the raw data, from 1955 through 1979 there were 21 cases out of 857 playoff games (2.45 percent) where a team overcame a double-digit deficit to win the game, but from 1980 through 2013 there were 84 such cases out of 2,477 playoff games (3.39 percent).
***
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 against the Grizzlies.
I have the play-by-play for that game, and amazingly the Grizzlies held a 24-point lead with less than 8:00 remaining in the game. From that point forward, though, the Clippers outscored the Grizzlies 28-3. That run included a brilliant stretch of shooting by Nick Young, as he nailed three 3-pointers in a 1:00 span to trim a 12-point deficit to just three points.