Three Key Stats: Barrett's Completion Percentage, Ohio State's Iffy Pass Defense, and the Buckeyes' Ability to Get in the Backfield Define the 2017 Season

Ohio State's 2017 season is in the record books. Fans will look back on the squad as largely a success story. The Buckeyes fell short of plausible national championship aspirations with two losses, both grisly defeats to Oklahoma and at Iowa. However, the Buckeyes beat Michigan again, won Urban Meyer's second Big Ten championship, and beat USC for the first time in seven tries in the Cotton Bowl.

Several stats will define how Ohio State fans remember the season. In this feature, we look over three key stats that in part shaped how the season unfolded.

J.T. Barrett Secured Another Record You May Have Forgotten

So much of the season hinged on J.T. Barrett's pursuit of various school and conference records in his redshirt senior year. Barrett's final season in scarlet and gray saw him secure multiple school and conference records, around 25 total. These include prominent places in the Ohio State record books for most total yards in a season (3,851), most touchdowns in a season (47), career passing yards (9,434), completions (769) and conference records for career passing touchdowns (104), total touchdowns (147), and career offensive yards (12,697).

There is one record J.T. Barrett got that flew under the radar, which also serves as a microcosm of his senior season. J.T. Barrett ended 2017 with the career completion percentage record (63.50%) previously held by Todd Boeckman (63.43%).

This record is unique because Barrett originally had it after 2014 and 2015. Had he left for the pros after his redshirt sophomore season, he would've easily had the career completion percentage record after completing 64.21% of his passes in his first two years. However, he lost this record after an inefficient 2016 season that saw him complete just 61.47% of his passes.

In other words, Barrett needed a better season in 2017 than he had in 2014 to get the record.

He did, but barely. Further, his trajectory to the record tells a tale of how his last two seasons largely went. Barrett struggled early and late. He secured the record largely on how hot he was in the middle of the season. The games against Nebraska and Penn State, in particular, gave him the record.

The six games after his career best performance against Penn State are him holding that record by the skin of his teeth.

Indeed, the granulars of the percentages tell how close Barrett was to losing this record again. After finishing 240/371 passing as a senior, he capped his career completion percentage at 63.50124%. Boeckman's completion percentage for a career was 63.43284%.

The difference is around 6/100ths of a percent.

The Passing Defense Underperformed Against Good Passing Teams and Overperformed Against Bad Ones

One retrospective evaluation of 2017 will pine for what it could've been with the secondary from 2016. Ohio State's 2017 offense with Ohio State's 2016 defense is probably a national championship team.

This largely concerns the secondary, which lost three members to the first round of the 2017 NFL Draft. The secondary that returned struggled mightily compared to the team before it. Indeed, Ohio State was the worst passing defense in the country after its first two games.

It will finish as the No. 30 passing defense, a climb of 100 spots from dead last. However, that's an overall regression to the mean since Ohio State opened its season with the No. 35 passing offense and the No. 3 passing offense.

Game by game, the data generally suggest a disappointing theme to Ohio State's passing defense. It overperformed against bad passing teams and underperformed against good passing teams.

It's not just the first two games either. Nebraska was a bad football team in 2017 but it had a capable passing attack that finished No. 27 in the country. It averaged 277.5 yards per game but had 349 passing yards against Ohio State. 

We can qualify that most of the damage was done after Ohio State was already routing Nebraska, but the data are still there and the trend is still consistent with what we saw against USC in the Cotton Bowl. USC averaged 299 passing yards a game but had 356 yards against Ohio State. The Trojans just couldn't finish drives in Arlington.

Ohio State had one objectively great overperformance against a good passing team. Penn State is 2017's No. 23 passing offense, averaging 290.2 yards per game. It had just 192 passing yards against Ohio State, though we can wonder if generous field position Ohio State conceded to Penn State (along with special teams blunders) explain part of that.

Beyond that, Ohio State was simply pummeling bad passing teams. UNLV is the No. 98 passing team. Ohio State held it to 88 passing yards. Rutgers is the No. 125 passing team in 2017. Ohio State held it to 92 passing yards. Maryland? No. 116 in the country in passing offense. Ohio State held it to 16 passing yards. Illinois? No. 106 passing team in 2017. Ohio State held the Illini to 16 passing yards in a monsoon.

Playing Army also helped. The Black Knights are dead-last of 130 FBS teams with 27.8 passing yards per game. Knowing Army's offense, this is not terribly surprising.

Ohio State Will End 2017 Leading the Country in TFLs

Ohio State had eight sacks and 14 total TFLs against USC. This is part of a general superlative for Ohio State in 2017: this was the best team for creating tackles in the backfield of the Urban Meyer era. Unless Alabama or Georgia have 25 TFLs in Monday's game, the Buckeyes will end 2017 as the No. 1 team in the country on this statistic.

The 14 TFLs against USC were largely responsible for getting it into a first place tie with Northern Illinois. The Huskies were previously No. 1 in TFLs and had eight in the Quick Lane Bowl loss to Duke. Ohio State had 14 against USC, getting the Buckeyes into a first-place tie. However, Ohio State (479) beats Northern Illinois (436) on TFL yards.

Ohio State has generally done well in TFLs since Meyer arrived. However, 2017 is the first year in which the Buckeyes will finish No. 1. It's previous best was in 2014, a fifth-place finish in part fueled by the presence of a 15th game.

This will be one fond recollection of Ohio State's 2017 season. The Buckeyes' defensive line was arguably the best in the country. It showed that through the whole season, and particularly against USC.