Ty Detmer set all kinds of school and NCAA records during his time at BYU from 1988 to 1991. A couple of those records stand in stark contrast to the output of the BYU offense since he took over as offensive coordinator in 2016:
- Most yards gained per attempt for a season – 11.1 (4,560 yards, 412 attempts) in 1989
- Most yards per completion for a career – 15.69 (15,031 yards, 958 completions)
Fast forward to 2016 and early 2017 and BYU is nowhere near those record numbers:
- Yards per attempt – 6.16
- Yards per completion – 10.32
But the problem isn’t that the current BYU offense isn’t threatening its own per attempt and per completion record numbers, it’s that they are well below what they need in order for BYU to consistently score points. It’s because yards per completion and points per game are two stats joined at the hip.
With 12 seasons of data and 17,420 games, the NCAA averages are 12.2 yards per completion and 27.3 points per game. Below is the graph showing the relationship of yards per completion to scoring across the NCAA
In the Portland State game, BYU averaged 12.1 yards per completion, which is right at the NCAA average, but the last two games they had 8.5 and 8.1 yards per completion against LSU and Utah respectively. The result? They averaged 6.5 ppg in those two games.
Over the last two seasons for BYU:
- 2016: 10.5 yards per completion, 29.5 ppg
- 2017: 9.5 yards per completion, 11.0 ppg
So how does all this relate to wins and losses? If a team averages 12 yards per completion, they win just above 50% of the time. If a team averages 8.5 or less (like BYU has the last two games) then they win 30% of the time.
There has been a trend over the last 15 years for passing offenses to trade off yards per completion with a higher completion percentage (aka “Dink and Dunk”). The problem with this approach, however, is that some teams have taken the dink and dunk to enough of an extreme that their increase in completion percentage is not sufficient to overcome the loss of efficiency resulting from the shorter throws. When the yards per completion drop below 12, it puts a lot of pressure on the completion percentage to be 65%, 70% or higher in order to have a better than even chance of winning a game.
In the last two games, BYU has completed 54% of their passes and averaged just over 8 yards a completion. Looking at the grid above, that translates to a win probability of 17%.
BYU has to figure out how to get the ball downfield more. That doesn’t mean they need to bombs away, but they have to throw past the sticks more often than they have to this point. The low yards per completion in 2016 is a big reason why 8 of BYU’s 13 games were decided by a TD or less and it’s an even bigger reason why BYU is 1-2 to start the 2017 season.