So we know how the point spread did overall, but how did it perform week to week? I thought you might ask that question. Here is how the spread performed week to week in 2012. Again, full disclosure: The Army/Navy game that technically occurred in Week 15 is included in the Week 14 results because it was the only game contested that week.
Finally, I decided to look at what percentages of the betting lines were within a given point total. I considered four ranges, and while they are arbitrary, I think they do a good job of sorting the numbers out. The ranges I used were 0-7 points (spread within one touchdown), 7.5-14 points (within two touchdowns), 14.5-20 points (almost three touchdowns), and 20 or more points (seemed like a good cutoff point).
Out of the 697 regular season games involving IA opponents, 261 of them (or 37.45%) finished within one touchdown of the betting line. In other words, more than a third of the time, you're hard-earned money was one play away from either nearly doubling or floating away. Think about that the next time your buddy has a 'sure thing'. Overall, over two thirds (67.00%) of the games finished within two touchdowns of the betting line and fewer than one of every five games differed by more than 20 points.
So we've seen how accurate the betting line is for the regular season. Is the bowl season, with its long layoffs, coaching upheavals, and differing levels of motivation equally as predictable or is it more of a crapshoot? That my friends, is what we in the business call a teaser. Stay tuned. :)