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INDIANALYTICS: Are the Hoosiers historically bad on defense?

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You know Indiana has a bad defense. But, compared to other high-scoring teams, is it historically bad? We examine the mess, and what it could mean for the Hoosiers' NCAA Tournament prospects.

Mary Langenfeld-USA TODAY Sports

Indiana's defense is not good this season.

This fact, unfortunately, cannot be denied. While our play have gotten worse on the defensive side of the ball without Hanner Mosquera-Perea, it wasn't exactly great to begin with. Going into last night's college basketball slate, the Hoosiers were ranked 248th in adjusted defense on KenPom's encyclopedic site, giving up 105.3 points per every 100 possessions. Thus, of the 351 teams in college hoops, only about 100 have a worse defense than the Hoosiers. Luckily, we're ranked 6th in offensive efficiency, which is saving us from what could be a disastrous season, and is the main reason we are 16-7 and still a tournament team right now.

Understanding our defensive woes, I decided to do a little research to see how bad it was compared to other Crean-coached IU teams, as well as other teams with a strong disparity between adjusted offense and adjusted defense ratings. As you'll see below, the results aren't exactly encouraging. (Note: all data is from before last night's games occurred)

First, let's take a look at Indiana itself since Crean took over before the 2008-09 season. Here's a quick chart I put together of the adjusted offense and defense ranking each year under Crean.

AdjO vs AdjD

Contrary to popular belief, IU has been able to play good defense in past seasons under Crean. In fact, I'd argue that it was our defensive pressure that kept the Hoosiers in many games last season, when our offense was anemic at times. And we did shut down Michigan, who had the best offense in the country in 2013-14, in Assembly Hall on Super Bowl Sunday last season. On the bright side, check out our offense - if we keep our shooting up this year, we'll be top 10 in the nation for three of the past four years. That's no small feat.

On the contrary, what makes this year's defense so striking is that it's an extreme outlier compared to a positive overall trend in defense over the six previous years. This graph helps to show how the Hoosier defense had been trending positively before this year began.

Our Defense Sucks

In the previous six seasons, you could see a correlation between time and improved defensive rating beginning to develop. Add in this year's data, however, and the correlation is completely gone. And while a similar drop happened with adjusted offense last year, it was not quite as pronounced as this year has been on defense. In fact, our defense is statistically much worse than Crean's first team, with its 6-25 record, that only allowed 102.2 points per every 100 possessions (which is still not great, but better than right now).

But let's also compare this team with other non-Hoosier teams. I decided to investigate how this year's IU squad has compared to other teams with a top-10 offense in recent years. And wouldn't you know it, but going back to the 2001-02 season (the earliest for which KenPom has data), this year's Indiana Hoosiers have the lowest-ranked adjusted defense of any team with a top-10 adjusted offense. That's right - there is no team with a top offense that has a greater disparity toward its defense. Yikes.

Despite this disparity, IU is still in line to make the NCAA Tournament. As of the latest Bracketology, the Hoosiers are a 7-seed. However, nothing is set in stone yet, and the Hoosiers have to get 4-5 more wins under their belt before Selection Sunday for me to truly feel comfortable. That being said, this year's team has made me wonder how other teams with great offenses and not-so-great defenses (outside the KenPom top 100) have done in the tournament in recent years. Thus, I looked back to 2009 to see the results of the teams that had these characteristics.

How teams with top-10 AdjO Rankings and sub-100 AdjD Rankings have fared in the NCAA Tournament

Year Team AdjO AdjD Result
2014 Michigan 1 109 Elite 8
2014 Duke 2 116 Round of 64 (Mercer lol)
2014 Iowa 5 120 Play-in Loss
2014 Iona 7 236 Did Not Qualify
2013 Iowa St 6 133 Round of 32 (The Aaron Craft Game)
2013 Colorado St 7 135 Round of 32
2013 NC State 9 112 Round of 64
2012 Mizzou 1 146 Round of 64 (Norfolk State lol)
2012 Creighton 6 190 Round of 32
2012 Purdue 9 125 Round of 32
2011 Colorado 9 199 Did Not Qualify
2011 Oakland 6 232 Round of 64
2010 Cornell 4 174 Sweet 16
2010 Notre Dame 7 131 Round of 64
2010 California 5 101 Round of 32
2009 Arizona 5 155 Sweet 16

So yeah, that's not a great sign even if we do make the tournament. Only one team with a sub-100 KenPom rating on defense advanced past the sweet 16, and that team had both a #1 offense, a wizard coach, and got bailed out of its Sweet 16 game on a bad call (but might have also made the final 4 if not for one of Aaron Harrison's bajillion clutch three-pointers last year). In addition, there have been two other teams prior to 2009 that had top-10 offenses and sub-200 defenses on KenPom - 2008 IUPUI, which had the #10 AdjO and #218 AdjD, and 2003 BC, with its #4 AdjO and #201 AdjD. However, neither of these teams made the NCAA tourney, meaning that teams with top-10 offenses and sub-200 defenses have only made the tournament once in four tries since 2002. Not good odds for our team that is living and dying by the three.

Thus, I would say not to expect for us to cut down any nets, but...

TOM CREAN THE CUTTER

Okay that joke was obvious. But I regret nothing.

Finally, we know that the Big Ten has a reputation for good, fundamentally sound, man-to-man defensive play. Well, either that or it just has low-tempo offenses with low-scoring games. As a result, I looked back at the B1G teams since the 2008-09 season and complied some stats on their adjusted defense ratings. In the past seven seasons, including this one, there have been 83 total seasons from which to look at data (11 teams in 2009-11, 12 in 2012-14, and 14 this year). Of all of the seasons, IU's adjusted defense of 105.3 is by far the highest one. On average, the KenPom adjusted defense rating for the Big Ten conference over this period of time is 95.94, and the standard deviation is 4.25. Thus, if you calculate the z-score (or standard score) of IU's defensive ranking this year, our defense is 2.2 standard deviations above the mean of 95.94. This means that you'd expect a B1G team to have a better defense than what IU now has about 98.6% of the time. (Note: one B1G defense before 2009 was ranked lower than us. This was a Northwestern team of the Bill Carmody era.)

In other words, Indiana's defense is not just bad when you watch them play. It's bad compared to other Crean teams, bad compared to other teams that had strong disparities between offensive and defensive performance, and terrible compared to other recent B1G teams. That being said, I may have picked the worst possible time to do this analysis, as IU has just come off giving up 92 points to a Wisconsin team that ranks first in adjusted offense in the country. In addition, Perea has now missed the past 7 games, and without him, our team's post presence has become nonexistent.

Can defensive play only go up from this point? Or will IU continue to have the largest disparity between the two sides of the ball of any top-10 offense in the past decade and a half? We've got only 8 more games to find out.