In a zero-sum game there's only room for 3 sides (max) of the Quadrangle of Hate to have good records at the same time. Someone has to be left out in the Quick Lane Bowl. For a long time that was us. Now it might be Nebraska. If they get better, that is.
Wisconsin loses Taylor, but returns Cohn / Cephus and most of their defense. I expect them to be very good defensively next year. They play Notre Dame OOC.
Minnesota loses most of their defense (Winfield pending) and one of their best receivers. I expect them to be very good offensively next year. They play a easy schedule next year.
Iowa loses their QB and a lot of trench players. I expect them to struggle next year.
Illinois found a real offense this year, but they lose their transfer QB so they will regress.
Purdue loses a lot of offensive production and probably won't compete again until 2021.
Nebraska loses most of their defensive front but returns essentially all of their offense. I expect them to be very good offensively next year, but they run into a buzz saw in crossover going to tOSU and then play PSU at home the very next week.
Northwestern will definitely be much better across the board next year.
The West isn't getting any easier with the investments they have made in their football programs over the last few years.
I think Wisconsin, Minnesota, and Nebraska will be vying for first place next year. It wouldn't surprise me if Minnesota / Wisconsin ends up deciding the division in early October.