Game Analysis

Best Bet – *Under (54.5) – Notre Dame  24   Iowa State  23

Lean – Iowa State (+3.5)

Both of these teams were really inconsistent offensively and the defenses for each team have the advantage in this game. Notre Dame averaged 6.3 yards per play but faced teams that would combine to allow 5.8 yppl to an average team averaged less than 6 yppl in 5 of their 12 games. Iowa State’s defense has a significant edge against the Irish attack, as the Cyclones yielded just 25.3 points and 5.3 yppl against teams that would combine to average 31.6 points and 6.3 yppl against an average defensive team. Notre Dame’s offensive rating is actually slightly less than the average rating of the offenses that Iowa State faced this season and my math projects just 5.15 yards per play for Notre Dame in what is expected to be inclement weather (likely rain with some wind). The Irish also had a tendency to play relatively worse against better defensive teams, as the slope of their yards per play as a function of their opponent’s compensated defensive yppl has a slope of 1.20. Anything above 1.0 indicates an offense that plays relatively better against weaker defenses and relatively worse against better defensive team. Ian Book was particularly inconsistent and built up his numbers with 13.6 yards per pass play in games against horrible defensive teams New Mexico and Bowling Green while mostly struggling against good pass defenses. Book averaged just 4.8 yards per pass play against teams that would 0.5 yppl better than average or more (Georgia, Virginia before losing All-American CB Hall, USC, Michigan, and Duke) and Iowa State’s pass defense rates at 1.1 yppl better than average (5.9 yppl allowed to quarterbacks that would combine to average 7.0 yppl against an average defense). Book’s slope predicting his yards per pass plays as a function of opponent’s pass defense is 1.43, so his relative performance level is particularly affected the quality of the opposing pass defense. In this case, Book would be projected to average only 5.32 yppp against Iowa State’s level of pass defense (including the weather adjustment), which is 0.45 yppp less than what the numbers would project if weighed all of Book’s pass plays evenly rather than putting more weight on his games against better defensive teams.

Iowa State’s Brock Purdy also has a couple of positive outliers against bad defensive teams that skewed his numbers up, as he averaged 13.8 yppp against ULM and Texas Tech. Purdy also had some good games against better than average defensive teams (7.8 yppp against Iowa, 9.7 yppp against TCU, 9.1 yppp against Oklahoma) but overall he was relatively worse against better defensive teams (although not the degree that Book is). Purdy is an accurate quarterback but his numbers are enhanced by a lot of big pass plays (5 games with a pass of at least 60 yards). However, Notre Dame’s defense allowed only 54% completions and did not allow a pass of over 50 yards all season. The Irish allowed just one quarterback (Jake Frohm from Georgia) to average more than 5.9 yppp against them, as they held the really good pass attacks of USC, Michigan, and Stanford (with Mills at QB) to a combined 5.7 yppp. Purdy’s regression equation as a function of opposing defense would project 5.25 yppp in this game and Notre Dame’s defensive regression equation yields a prediction of 5.28 yppp for the Cyclones in this game. Both are lower than the 5.44 yppp that would otherwise be predicted.

My math model liked the under here even before using the regression analysis to dampen the affect of the positive outliers against bad teams by each offense and now I think there is even more value. Part of the reason for the high line could based on the scoring of these teams, as the compensated points model would project 55.5 total points. However, both teams had very high combined redzone efficiency numbers, as Notre Dame’s games averaged 5.7 points per redzone opportunity (offense & defense combined) while Iowa State’s games averaged 5.4 points per RZ. The national average is 4.9 ppRZ and Notre Dame’s combined average is extremely high (I’ve never seen higher) and certainly unlikely to continue while Iowa State’s combined ppRZ is also due to regress towards expectations, as is the Cyclones’ 42.6% 3^rd-down conversions allowed on defense, which is particularly high given how good their defense is overall.

My math model actually projects just 44.2 total points based on the projected stats but I decided to assume a higher points per redzone opportunity than my model would project. That gets the projected total up to 46.6 total points, which uses the overall scoring efficiencies of these two teams instead of the scoring efficiencies expected given the projected stats. Despite the unusually high combined points per redzone numbers, the Irish went under in 7 of 12 games and Iowa State also was under in 7 of 12 games in regulation (they went over vs Northern Iowa due to 29 OT points). If the redzone numbers regress some towards the mean then this game should go under with room to spare. I’ll go Under 54 points or higher in a 1-Star Best Bet.

While the math favors Notre Dame by 2.4 points, I’ll call for a slightly lower margin based on a 25-80-1 ATS bowl situation that applies to the Irish. Brian Kelly is also just 3-7 ATS in bowl games in his coaching career, including 0-3 ATS laying points. I’ll lean with Iowa State at +3 or more.