From 2000 to 2012, there were 624 games in which a team trailed by 19 with 2 minutes left in the third. In just 12 of those games (1.9%) did the trailing team go on to win. But that includes all games, including those in which a heavily favored team fights back from a steep deficit.
The Rockets were 8.5 point underdogs against the Clippers, and heavy underdogs rarely pull off what Houston did last night. Here is the raw data from the 2000-2012 NBA seasons (the raw data behind my win probability model).
|two minutes left in the third:|
|all games||7.5 to 12 pt underdogs|
Out of 193 games, not a single underdog of 7.5 to 12 points came back from a 19 point deficit. These raw numbers are fairly consistent with the two win probability graphs for this game (by design):