Louisville has lost four of seven, and this has taken a lot of the focus off what was once the No. 1 team. What is being lost in the shuffle is that they're defending as well as anyone. We all knew that Pitino's defense was going to be good – they did have the best defensive efficiency in the nation last year – but I'm not sure we knew exactly how good.
The Cardinals are once again leading the nation in defense. They allow just 81.9 points per 100 possessions (adjusted for strength of schedule), compared to the national average of 100.0. It's slipped a bit in conference only play but that's primarily due to two games where Syracuse and Notre Dame lit them up with bizarre numbers. Even with those two games they still have the No. 1 defensive efficiency in conference only games.
The primary difference between this year and last year is that they're turning teams over at a higher rate, and they're doing a better job on the defensive glass. Last season Louisville ranked No. 37 and No. 230 in those two categories nationally, and this year they've improved to No. 2 and No. 173.
I looked at every team in the past decade to see where the Cardinals overall defensive efficiency (81.9 per 100 possessions) stood. They've still got games to go, but as of today they have the best efficiency in that time period. Here are the teams:
| team | year | dEff | |
| 1 | Louisville | 2013 | 81.9 |
| 2 | Kansas | 2007 | 82.2 |
| 3 | Memphis | 2009 | 82.5 |
| 4 | Florida | 2013 | 82.6 |
| t5 | Kansas | 2008 | 82.8 |
| t5 | Wisconsin | 2008 | 82.8 |
| t7 | UCLA | 2008 | 83.9 |
| t7 | Memphis | 2008 | 83.9 |
| t7 | Louisville | 2004 | 83.9 |
| 10 | UCLA | 2007 | 84.0 |
There have been eight previous teams to finish the season below 84 points per 100, and Louisville appears to be pushing to become No. 9.
The problem is that the average basketball team isn't scoring as much per possession as they have in the past. Offense is down (or defense is up, depending on your perspective). The 100 points per 100 possessions is the worst offense in the past decade, which takes a bit of the shine off of what Louisville is doing. To find out how much of that shine is missing I compared those same ten defenses to the average defense within each of their respective seasons. That changes things:
| team | year | dEff | avg | % dif | |
| 1 | Kansas | 2007 | 82.2 | 101.8 | 23.8% |
| t2 | Kansas | 2008 | 82.8 | 101.9 | 23.1% |
| t2 | Wisconsin | 2008 | 82.8 | 101.9 | 23.1% |
| 4 | Memphis | 2009 | 82.5 | 101.1 | 22.5% |
| 5 | Louisville | 2013 | 81.9 | 100.0 | 22.1% |
| t6 | UCLA | 2008 | 83.9 | 101.9 | 21.5% |
| t6 | Memphis | 2008 | 83.9 | 101.9 | 21.5% |
| 8 | UCLA | 2007 | 84.0 | 101.8 | 21.2% |
| 9 | Florida | 2013 | 82.6 | 100.0 | 21.1% |
| 10 | Louisville | 2004 | 83.9 | 100.8 | 20.1% |
Since the average scoring is down, Louisville drops to 5th in the past decade. The 2007 Kansas team, which won the Big 12 regular season and tourney titles, moves to the top. That Kansas team came up short in the NCAA Tournament and got knocked out in the elite eight in a game where they struggled to score against UCLA (No. 8 on the above list). The Jayhawks' offense that year was ranked No. 17 in the nation. Louisville's offense this year? No. 17.
