The first half of the Big Ten schedule is in the books, and Northwestern finished up at a disappointing 3-6, good for 9th place in the conference. To figure out exactly what's going wrong, I decided to take a closer look at some offensive and defensive efficiency stats. All stats are taken from Ken Pomeroy's website.
On offense, Northwestern has averaged 103.78 points per 100 possessions during Big Ten play. In terms of raw efficiency, that would rank them 128th in the nation out of 347 teams, not great. However, there is a strength of schedule issue here, as all 9 of their conference games have been against teams in the top 71 nationally in defensive efficiency, with 7 coming against teams in the top 40 nationally (Illinois is 71st, everyone else is 37th or better). So the offense has been doing fine, as they can still score at a decent rate against some of the nation's best defensive teams. All the shot clock violations that symbolized Northwestern's offensive futility have pretty much disappeared this season, and while there's certainly room for improvement, the offense has not been the problem.
On defense however, the 'Cats have been torched during conference play, allowing 112.56 points per 100 possessions. That would rank 342nd (or 6th from the bottom) in the nation in raw efficiency, obviously a terrible total. Again, strength of schedule has to be taken into account here, as 5 of the 9 league games have been against teams in the top 30 nationally in offensive efficiency (Michigan State twice, Purdue, Ohio State, Wisconsin). Still, that kind of defense just isn't going to get it done. If you've been watching the games, all these stats aren't necessary, as you've seen how bad the defense has been at times. The 'Cats have been completely unable to get stops for long stretches, namely the second half of both Michigan State games, almost the entire Ohio State game, the last 10 minutes against Wisconsin, and the second half and overtime in the first Illinois game.
Looking further at the stats, one thing that really stands out is how few turnovers Northwestern has forced. For the season, they are only 158th in the nation in forcing turnovers at 21% of opponent's possessions, and that has gone down to 17.4% in conference play. That number is way down from last year, when the 'Cats ranked 12th in the nation for the season in forcing turnovers, at 24.4%. Forcing turnovers isn't a requirement for being a good defensive team, as neither Michigan State nor Wisconsin force very many and are still two of the nation's best. However, if you're going to play almost entirely zone defense, and a lot of trapping 1-3-1 zone at that, forcing turnovers becomes necessary. In the 1-3-1 in particular, the goal of the defense is to force guards to turn the ball over, as if opponents can get the ball past the zone, the interior is wide open. Additionally, it is hard to rebound out of the 1-3-1, so teams often end up with second and third chances. Northwestern is in the middle of the pack nationally at defensive rebounding, a big improvement over most of the Carmody era, but still not great. So if you're not forcing turnovers, you're not going to get stops playing 1-3-1. In the second half against Michigan and Minnesota, the 1-3-1 was forcing turnovers and was a key factor in Northwestern getting back into those games, but for the most part it hasn't been working. I would really like to see Carmody play less 1-3-1 and more straight up man to man. He's played mostly matchup zone when not in the 1-3-1, and I think it's been more effective for the most part. It usually manages to clog the middle and forces teams to beat it from the perimeter, which worked very well against Purdue, Notre Dame and Iowa State to name a few.
Unfortunately, from watching this team almost every game, I've come to the conclusion that Northwestern is not a well coached defensive team. Talking to Wisconsin bloggers earlier this season, I asked what makes Bo Ryan such a great coach:
He wins by taking secondary talent and forcing them to play mistake-free basketball. Most people look at turnovers when they talk about not making mistakes, but check out Wisconsin’s defense Wednesday. Ryan only plays guys who have the right footwork to stay in front of their man and if they reach or violate any of his "rules" then they will be on the bench at the next whistle.
I don't think I have ever seen Bill Carmody take a player out immediately for a defensive mistake. He will often pull a player for making a mental mistake on offense (bad shot selection, forcing passes to people who aren't open, etc.), but never for defense. While some people criticize his Princeton offense, I think it's been pretty successful both this year and last, and he is very well respected by his peers as an offensive mind. But I have a lot of doubts about his defensive coaching. With the talent he currently has, his teams shouldn't be getting torched the way they have been, and often it comes down to poor fundamentals. One example is that his players tend to be out of control while closing out on perimeter shooters, and end up out of position. Another is that help defense is often non-existent. Too many times, an opponent will beat his man off the dribble, and no one will rotate over to help.
In past years, when Northwestern had minimal talent, it was understandable that they couldn't get stops. But now, with a rotation full of players athletic enough to compete in the Big Ten, there are no more excuses. The 'Cats perimeter offense is going to have bad nights sometimes, and they'll need the defense to bail them out. And right now, the defense isn't capable of doing that. Hopefully this trend turns around soon, as Northwestern can't afford many more losses if they want to make the NCAAs.