There is a lot of talk about the large point spread in the Patriots/Texans game. New England is a 15.5-point favorite over Houston tonight, tied for the second largest spread ever in a non-Super Bowl playoff game behind only Minnesota/Arizona in 1998. The over/under is 44.5, which means the projected final score is 30-14.5.

Let’s say the Texans pull off the upset. Are they more likely to do so in a low-scoring game, or in a shootout? If Houston wins 14-13, they will have come in under their projected points total by 0.5, but held New England to 17 fewer points than expected. If the Texans win 31-30, they would have exceeded their projected points total by 16.5 points, while holding New England to exactly the number of expected points.

So, which result is more likely? My intuition says a low-scoring game, but what do the numbers say? There have been 24 games since 1985 where a team won despite being an underdog of at least 14 points. As it turns out, intuition is correct: on average, these underdogs exceeded their projected points for total by 7.8 points, but held their opponents to 13.3 fewer points than expected.

Team Opp Year Wk Boxscore Line Over/Under Proj PF Proj PA Act PF Act PA PF Diff PA Diff ram nor 2011 8 Boxscore 14 48.5 17.25 31.25 31 21 13.75 -10.25 min phi 2010 16 Boxscore 14.5 44.5 15 29.5 24 14 9 -15.5 rai pit 2009 13 Boxscore 15 37 11 26 27 24 16 -2 tam nor 2009 16 Boxscore 14 48.5 17.25 31.25 20 17 2.75 -14.25 rai den 2009 15 Boxscore 14 37 11.5 25.5 20 19 8.5 -6.5 rai phi 2009 6 Boxscore 14 40.5 13.25 27.25 13 9 -0.25 -18.25 det dal 2006 17 Boxscore 14 46 16 30 39 31 23 1 htx mia 2003 1 Boxscore 14 34.5 10.25 24.25 21 20 10.75 -4.25 htx pit 2002 14 Boxscore 14 37.5 11.75 25.75 24 6 12.25 -19.75 crd phi 2001 4 Boxscore 14.5 41 13.25 27.75 21 20 7.75 -7.75 nwe ram 2001 20 Boxscore 14 52.5 19.25 33.25 20 17 0.75 -16.25 cle pit 1999 10 Boxscore 14.5 34.5 10 24.5 16 15 6 -9.5 was dal 1995 14 Boxscore 17 46 14.5 31.5 24 17 9.5 -14.5 car sfo 1995 10 Boxscore 14 40 13 27 13 7 0 -20 nor sfo 1995 9 Boxscore 14 44.5 15.25 29.25 11 7 -4.25 -22.25 ram kan 1994 4 Boxscore 14.5 44.5 15 29.5 16 0 1 -29.5 ram nor 1993 15 Boxscore 14 36.5 11.25 25.25 23 20 11.75 -5.25 nyj buf 1992 14 Boxscore 17 36 9.5 26.5 24 17 14.5 -9.5 clt buf 1992 13 Boxscore 16.5 41 12.25 28.75 16 13 3.75 -15.75 ram dal 1992 11 Boxscore 14.5 40 12.75 27.25 27 23 14.25 -4.25 dal was 1989 9 Boxscore 14 45.5 15.75 29.75 13 3 -2.75 -26.75 atl sfo 1988 3 Boxscore 14 44 15 29 34 17 19 -12 nor sfo 1985 4 Boxscore 16 45 14.5 30.5 20 17 5.5 -13.5 phi was 1985 3 Boxscore 14 42 14 28 19 6 5 -22 Avg Boxscore 7.8 -13.3

In fact, only once — a week 17 upset win by Detroit — did a 14-point (or worse) underdog win despite allowing more points than projected or over 24 points. Perhaps the best model for a Texans win today would be this JaMarcus Russell-led upset over the Eagles in 2009, when Oakland won 13-9.