Northwestern is off to a promising start to the season at 6-0, even managing to beat some decent teams in non-conference play for once. It's a bit early in the season for this, but with six games worth of data in the books, let's look at some statistical trends to see how Northwestern compares to past years. All of these numbers are from the excellent Ken Pomeroy's Northwestern page on his website ($$$$).
Effective field goal percentage: 53.9%, 36th nationally: Northwestern is shooting the ball well as they have the last few years. Nothing surprising about this.
Three point field goal percentage: 33.6%, 167th nationally: This is down significantly from last year's 37.5%, a drop off that can be largely explained by the absence of Michael Thompson, who hit 40% of his threes even as a high volume shooter. Dave Sobolewski has been solid this season but he's not close to the kind of shooter Thompson was.
Two point field goal percentage: 56.7%, 9th nationally: NU is doing an excellent job on two point shots. Part of this can be attributed to the Princeton offense that gets lots of lay-ups on backdoor cuts, but it's also due NU having some athletes that can finish at the rim. Drew Crawford in particular has really elevated that part of his game, hitting 62% of his twos so far this season.
Free throw rate: 37.8%, 150th nationally: Free throw rate (Free throw attempts over field goal attempts) is a measure of how often a team gets to the line. NU is usually near the bottom of the country in this stat, so being in the middle of the pack nationally is a solid step in the right direction. Any team that takes a lot of threes won't be great at getting to the line, but NU has more players attacking the basket this season, bringing us to...
Assists per field goals made: 59.1%, 65th nationally: Under Bill Carmody, Northwestern has always been among the national leaders in this category. Commentators use this stat to laud NU for their unselfish play, but I think in many ways leading the nation in this category is a bad thing, as it means you don't have anyone who can create his own shot. So I think it's a good thing that NU is ranked a little lower than they have been in the past, as it means there are more players getting baskets on their own off dribble drives.
Turnover percentage: 13.7%, 5th nationally: NU is always among the best in the country at not turning the ball over, no surprise here.
Offensive rebound percentage: 23.3%, 327th nationally: NU has almost always been last in the Big Ten in offensive rebounding, in large part due to the offensive system they run. Ideally, they'd be better at offensive rebounding, but the offense is very efficient despite this so it's not a problem.
Opponents effective field goal percentage: 47.1%, 130th nationally: This is not a great total, but NU was 311th in this category last season, so it's a step in the right direction. However...
Opponents three point field goal percentage: 28.1%, 50th nationally: On paper this looks like good defense, but in reality it's mostly dumb luck. Also, the total is skewed by Texas-Pan American hitting just 3 of 23 threes in the season opener. NU plays a lot of 1-3-1 zone, and against that defense opponents will generally be able to get open three pointers. Eventually, Northwestern will face Big Ten teams that can shoot and this number will get a lot worse. There is also a huge variance component in three point percentage over such a small sample size. In 2009-10, NU got off to a great start in non-conference play and their defensive stats looked pretty good on paper, but it was largely due to teams like Notre Dame and NC State shooting horrendously on open threes against the 1-3-1. An effective 1-3-1 does many things well, but stopping the opponent from getting good looks from three isn't one of them.
Opponents two point field goal percentage: 50%, 226th nationally: This looks bad, and it is, but it beats last year when NU was 326th in this category.
Blocked shot percentage: 12.4%, 65th nationally: A large part of the reason for the two pointer defense improving is that NU is blocking more shots. John Shurna in particular has been excellent in this category.
Opponents offensive rebound percentage: 37.2%, 290th nationally: This is a horrifically bad total for Northwestern, even considering they play a lot of 1-3-1 zone which is difficult to rebound out of. I don't expect NU to keep being this bad, as they were much better than this last year, but it's an alarming trend. The biggest reason for the terrible defensive rebounding has been the surprisingly poor play of Luka Mirkovic, who is way below his career rebounding averages. Luka averaged nearly 9 rebounds per 40 minutes each of the last two years, but so far this season he's at just 4.2 per 40 minutes. No one as tall as Luka not named Vince Scott could post a rebounding rate that bad for a full season, so this should improve.
Opponent's turnover percentage: 23.8%, 80th nationally: In 2008-09, the only thing NU did well on defense was force turnovers, but the last two seasons their turnover rate fell off and the defense suffered. So it's nice to see the turnover rate improving this year, although I have questions about whether they can continue at this pace.
Opponents free throw rate: 25.4%, 17th nationally: NU is doing a great job so far at not fouling, something they haven't been very good at the last few years. With their lack of depth, staying out of foul trouble is important, so it's nice to see them fouling so little. I would expect this to regress toward the mean as the season continues, but you never know.