The big news this week is that Northwestern is out of the cellar, ahead of Illinois. It doesn't look good for Illinois going forward, either. The last two columns show each team's remaining strength of schedule (big red numbers are bad) and rank. Illinois has by far the toughest remaining schedule.
Nebraska and Ohio State have the easiest remaining schedules. Ohio State's easy schedule is bad news for Wisconsin's hopes of getting the 4-seed in the Big Ten tournament. At this point, I think there's a better chance of passing Iowa, considering that Ohio State will have the tiebreaker over Wisconsin. Wisconsin will have a chance to take matters into its own hands: if it can win at Iowa, that would be huge. (This is unlikely, but a guy can dream.)
Overall, the gap between number 1 and number 12 in adjusted efficiency this year is remarkably small. I've done these calculations now for 2012 and 2013, and the final spreads were much larger:
So the bottom of the league is much better than it has been recently. But the top of the league also isn't as good. In last year's final Kenpom ratings, the Big Ten had four teams in the top nine: Indiana (3), Michigan (4), Ohio State (7), and Michigan State (9), and Wisconsin wasn't far behind at 13th. This year, the Big Ten's big five (same teams, except replace Indiana with Iowa) are all currently rated between 11th and 17th—solid, for sure, but no one spectacular.
No dominant teams plus no cupcakes equals craziness. That's Big Ten basketball this year.
Edit: It occurs to me that comparing the final numbers from 2012 & 2013 to this year's mid-season numbers might not be a good idea. Although these numbers are "per possession" they are also "per possession compared to average" so it's safe to assume they'll widen as the season goes on. I did a quick check on the 2013 numbers, and after 59 games that year the gap between 1 and 12 was .40 (the final gap was .58). Still, that's significantly larger than the .26 gap this year.