That didn't take long, I looked at the entire Collins era, comparing OOC versus Big Ten.
As I suspected, this year is a huge outlier:
OOC versus Big Ten, FT differential per Game
13-14 NU 310 Opp 338 -1.86/G NU 286 Opp 342 -3.1/G -1.24 14W v 19L
14-15 NU 241 Opp 267 -1.85/G NU 236 Opp 304 -3.77/G -1.92 15W v 17L
15-16 NU 255 Opp 275 -1.42/G NU 273 Opp 350 -4.27/G -2.85 20W v 12L
16-17 NU 329 Opp 364 -1.94/G NU 308 Opp 368 -3.33/G -1.39 24W v 12L
17-18 NU 291 Opp 286 +0.35/G NU 247 Opp 335 -4.88/G -5.23 15W v 17L
18-19 NU 250 Opp 202 +4.36/G NU 265 Opp 343 -4.33/G -8.69 12W v 17L
Negative 8.69 Free Throws, that's per game! That's the differential from OOC play to Big Ten play. I knew this year would be more extreme than other years, but that's more than I would have imagined.
I don't have time to do this for every other Big Ten team, but if anyone can find a differential greater than -8.69, I'll gladly send you a reward.
As I suspected, this year is a huge outlier:
OOC versus Big Ten, FT differential per Game
13-14 NU 310 Opp 338 -1.86/G NU 286 Opp 342 -3.1/G -1.24 14W v 19L
14-15 NU 241 Opp 267 -1.85/G NU 236 Opp 304 -3.77/G -1.92 15W v 17L
15-16 NU 255 Opp 275 -1.42/G NU 273 Opp 350 -4.27/G -2.85 20W v 12L
16-17 NU 329 Opp 364 -1.94/G NU 308 Opp 368 -3.33/G -1.39 24W v 12L
17-18 NU 291 Opp 286 +0.35/G NU 247 Opp 335 -4.88/G -5.23 15W v 17L
18-19 NU 250 Opp 202 +4.36/G NU 265 Opp 343 -4.33/G -8.69 12W v 17L
Negative 8.69 Free Throws, that's per game! That's the differential from OOC play to Big Ten play. I knew this year would be more extreme than other years, but that's more than I would have imagined.
I don't have time to do this for every other Big Ten team, but if anyone can find a differential greater than -8.69, I'll gladly send you a reward.