I think you can do a meaningful comparison of coaches by taking the number of games they won in a given season that they were expected to lose, and subtracting the number of games they lost that they were expected to win.
There are also successful coaches who get outcoached in the NCAA tourney when their teams get beat by a much higher seed.
And then you have the coaches who turn around a moribund program, pull them out of the abyss and turn them into a competitive team that is capable of beating anybody. That’s where Pike is now.
Cover Percentage and Rank in Big Ten by Year:
2018-2019: 53.3%/4th
2017-2018: 53.8%/6th
2016-2017: 50%/8th
Not exactly what you were looking for but found it mildly interesting nonetheless.
Found some data in regular season. Working on 2018-2019. UPDATED w/ 2018-2109.
2016-2017 Wins as underdog:
DePaul +2
Nebraska +2
Penn St +8
3-16 Straight up as underdog(~.126 wins below expectation)
2016-2017 Losses as favorite:
Penn St -2
Iowa -1
10-2 Straight up as favorite
2017-2018 Wins as an underdog
Seton Hall +8
Wisconsin +3
Iowa +1
Northwestern +3
4-15 Straight up as underdog (~.229 wins over expectation)
2017-2018 Losses as Favorite:
Stony Brook - no line
Hartford - no line
Nebraska -2
9-3 Straight Up as Favorite
During this time frame:
Favorite: 19-5
Underdog 7-31
Underdogs against Pikiell Win Percentage: .208
Pikiell as an Underdog Win Percentage: .184
2018-2019 Wins as Underdog
Miami +10.5
Ohio St +5
Nebraska +8.5
Penn St +7
Indiana +1.5
Northwestern 5.5
Iowa 8.5
7-15 Straight Up as Underdog: .318 win percentage as underdog (~1.5 wins above expectation)
2018-2019 Losses as Favorite
Fordham -8
7-1 Straight Up as a Favorite: .125 Underdog win percentage against Pikiell
Career to Date at Rutgers:
Favorite: 26-6
Underdog: 14-46 (~1.6 wins over expectation)
Underdogs Win Percentage Against Pikiell: .187
Pikiells Win Percentage as Underdog: .233
Pikiells 2019 Win Percentage as Underdog: .318
NCAA Underdogs Win Percentage: .257