I need to find the stats for 3rd down opponents conversion pct, but with breakdowns by down and distance as well as by quarter. In the overall numbers, Nebraska was in the mid 40's in that pct. I would bet the 4th quarter numbers were not that good, and specifically late in 4th quarters. I don't necessarily think it was fatigue that was the difference. I am of the opinion that Nebraska played more base D, with little to no blitzes in those 3rd down scenarios. If that were to be proven accurate, I am not sure whether that would be from a lack of confidence in the secondary to play man up or just the offensive formation that dictated more base D.
With 4th down conversions Nebraska actually ranked in the top 15 allowing 9 conversions in 23 attempts, again I would love to see the data with distance to go and at what point in the game the 9 conversions took place. 2 of the conversions were against Michigan, so those are irrelevant but the remaining 7 could have been the difference between 5-7 and 6-6 or 7-5.
If anyone has a site with that info, I would love to see it.