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:
|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:
|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:
|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:
|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.