IMO DeBoer's the main reason (after tonight I'm tempted to say the ONLY reason) IU was even in the Gator Bowl with 8 wins.
In one season DeBoer improved IU's B1G 10 scoring offense from 12th to 6th, its total offense from 7th to 3rd, its rushing offense from 11th to 9th, its pass efficiency from 9th to 4th, its TOP from 11th to 2nd, and led the conference in passing offense, ahead of Brohmbardi, Michigan with Shea Patterson, Minnesota with Coach Row-THIS-Boat, and tOSU with Justin Fields.
I suspect, given how the D played during the regular season, that if IU had been running Debord's offense again in 2019, 6 wins might have been its ceiling--they easily could have lost to PU and/or Maryland/Nebraska and, frankly, I wouldn't have been completely shocked if (again, w/ the 2017-18 offense) they had found some way to blow the Ball State game (probably with some special teams mistake).
IU fans should be thankful we even had DeBoer for one season, and should hope and pray that Allen can find a replacement of similar quality, because it appears such a hire will be crucial to overcome some apparently unresolved clock-management and special-teams issues.