Heading into the second year of Jonathan Smith's tenure at leading Michigan State, I don't think it is unfair to posit that the fortunes of MSU football in 2025 are tied to those of one Aidan Chiles, the Spartans' starting quarterback.
Chiles' turnover prone ways drove a lot of discourse in 2024, and his improvement in this regard will be a key area of focus in the coming season. Looking at the schedule, one can see that in the first half last season, (including a turnover-less romp over Prairie View A&M), Chiles accounted for four fumbles lost and eight interceptions. In the back half of the season, Chiles lost only one fumble, and threw only three interceptions.
Facially, this looks encouraging, a tale of a player improving over the course of the season. Additionally encouraging is the fact that of the 16 turnovers that Chiles had, only seven came against what I would qualify as the best defenses on the schedule (one fumble each against Ohio State, Oregon and Michigan, and singular interceptions against OSU and Iowa, and two against a playoff-bound Indiana team.) While it may not seem encouraging that a majority of Chiles' turnovers came against what I would consider subpar teams, it's an indisputable fact that most of those occurred earlier in the season: one fumble each against Maryland and Florida Atlantic (recovered by MSU), three interceptions versus Boston College, and two each vs. UMD and FAU.
Chiles clearly cleaned up his game later in the season, playing largely clean games against Michigan, Illinois, Purdue, Rutgers and Iowa. However, three of those five games were losses, with Rutgers being particularly uncompetitive to conclude the 2024 campaign. Taking aside the fact that there were issues on the defense and offensive line, what can we glean from Chiles' play in the back half of the year to project to this coming season?
In trying to game out whether Chiles' apparent increase in efficiency was a result of his improvement as a quarterback, or a shift in play-calling that resulted in decreased turnovers, I first consulted Pro Football Focus.
I considered the Iowa game the hinge point of the 2024 season, for two reasons. Firstly, it conveniently marks the halfway point of the season. Secondly, it was Michigan State's best played game, and the marquee victory of the season. I thought that it would be a springboard to a rivalry win and bowl eligibility.
While that did not happen, Chiles did play much more clean from the Iowa game through the end of the season.
I did not see, as I thought may have been the case, a dramatic decrease in pass attempts for Chiles starting in the Iowa game. In other words, the decrease in turnovers was not due to the coaching staff taking the ball out of Chiles' hands to prevent game-altering turnovers. I also looked at gap/zone run splits to see if there was a philosophical change in the back half of the season, but none was apparent. I also did feel that the gap/zone splits showed a differing play-calling approach in wins versus losses, or close games versus noncompetitive games.
Take a look at the chart below (numbers courtesy of PFF).
In large part because MSU spent significant amounts of time trailing in the final five games of the 2024 season, the majority of Chiles' snaps were pass attempts in three of the last six games, including three of the four losses in the back half of the season. Offensive coordinator Brian Lindgren clearly favored a balanced run/pass split (comparing the splits in wins versus losses bears this out), but Chiles was able to handle increased numbers of passing attempts in the back half of the season and not suffer the turnover issues that plagued him against Maryland, Boston College and FAU.
I did find interesting the insight that PFF was able to give on Chiles' heat map, or where he threw the ball.
On deep throws, over 20 yards, he threw three interceptions and had relatively low completion percentages, which is to be expected and is acceptable.
Throws under 10 yards were fairly kind to Chiles. This makes sense, considering his comfort completing curl or hitch routes underneath against off-coverage, and targeting tight ends on quick-hitting out routes. There were a couple of interceptions over the middle, which in my view were largely cleaned up by midseason.
Critically, Chiles was nearly perfect on throws at or behind the line of scrimmage. This matters hugely on smoke routes, wide receiver screens and running back screens that are designed to be plays that create yards after the catch. For such plays, making a receiver hesitate or turn out of stride to catch a ball is a kiss of death — Chiles largely avoided this.
The issues for Chiles emerged mostly in intermediate throws between 10 and 20 yards. This is also not surprising, as it is where most coverage variance occurs. Normally, you can get a solid idea presnap of how the secondary players are going to be playing the deep quarters of the field, and coverage in the deep middle of the field is almost always governed by the actions of one of the safeties. The complexities with defensive structure often are most pronounced in the intermediate middle, where linebackers, safeties, nickels/hybrid space players, and occasionally defensive ends switching responsibilities trouble reads for the quarterbacks and cause hesitation or missed throws. The defensive focus on the intermediate middle makes sense, as it is the area most visually available to the quarterback, and every route concept attacks this area in some way.
Chiles had a much higher completion percentage on his arm side, the intermediate right. However, he threw five interceptions over the intermediate middle, often directly to a linebacker that either tipped or intercepted the throw. This is again unsurprising, but provides a bit of clarity into how defenses found effectiveness against Chiles.
Having concluded that a change in the number of pass attempts or a wholesale offensive philosophy change did not result in the decrease in turnovers in the late part of the season, I had the welcome task of reevaluating Chiles' performance and the down-to-down offensive architecture in the back half of the season to see what worked.
