Is the Aggressive Defense Worth it?

During the two-part Big East Preview, there were a number of questions that popped up in the MUScoop.com thread. One poster, Pardner, who has helped contribute information regarding Official Bias, wondered if we were going to see any change in the fact that TC's teams always outfouled the competition. So I decided to look into this a little bit further.

If you look at the 2007 Pomeroy Marquette page and the 2008 Pomeroy Marquette page, one can see Marquette's Defensive Free Throw Rate (FTA / FGA) ranking. In the last two years, Marquette ranked #236 (in 2007) and #262 (in 2008). Despite being a Top 15 team according to Pomeroy, Marquette was one of the worst teams in the country at preventing opponents from getting to the line. Last year Marquette fit in comfortably between Albany and Sacred Heart. yeesh

While one could say that this is a product of our guard-centric lineup and big man deficiency, I don't believe that roster mix is the reason. After all, Marquette put our opponents on the line more regularly than South Carolina Upstate. (did you even know that was a school? yes, they exist)

Instead, I attribute this more to our defensive philosophy, which is commonly known as an aggressive style defense that favors deflections and steals. In fact, my key assumption is that the there is a link between the aggressive style of defense, increased opponent turnovers and more fouls committed. Marquette had a stingy and thieving defense last year, ending up #11 in the country at steal percentage. We forced turnovers (#49 in the country), and when the defense was working we were off and running for easy points.

But was the defensive strategy worth it?

If you look at the Pomeroy Game Plan for Marquette, you'll see that Marquette had a 99% significant correlation between our Opponent's Free Throw Rate and our Defensive Efficiency. In other words, when our opponent had a good Free Throw Rate, our defense suffered. (As I say all the time, it sounds intuitive, but it's not the same for every team. It doesn't apply to Wisconsin) We allowed our opponents to have a FTR of 41% last year. That means that an average opponent, shooting 54 FGA, would also take 22 free throws. To repeat, this was #262 in the country.

Against Top 100 opponents, the story is even worse. Our opponent's FTR goes up to 46% (~25 Free Throw Attempts per game).

Yeah, but so what? The average impact of this Free Throw Rate was a worsening of our Defensive Efficiency of 26.2, with a range from 16.9 (low) to 35.5 (high). Keep in mind our season Defensive Efficiency was 87.8, so this impacted our defense by 20-40%. I calculate that the way we put opponents on the line cost Marquette an average of 17.8 ppg with a standard range from 11.5 ppg to 24.2 ppg.

As previously stated above, Marquette's aggressive defense was one of the best in the nation. How much did we benefit from our aggressive defense? Going back to the Game Plan, we also see a 99% significant correlation between our Opponent's Turnover Rate and our Defensive Efficiency. More turnovers from our opponent means that our defense was better. (Still sounds intuitive, but it doesn't apply to Pittsburgh). We forced opponents into a turnover rate of 23.4%, meaning that our opponents ended up with about 16 turnovers per game, or almost one out of every four possessions.

Against Top 100 opponents, the turnover story is also not as good. Better teams protect the ball more. We only forced opponents into a turnover rate of 21.7%. Remember that 20% is considered average (a turnover one out of five possessions).

We come back to the so what? The average benefit on our defense was an improvement of our Defensive Efficiency of 13.2 with a range from 10.2 to 16.3. On a percentage basis, this is about 10-20% of our defensive results. I calculate that the turnovers for our opponents cost them (and benefited Marquette) an average of 9.0 ppg with a standard range from 6.9 ppg to 11.1 ppg.

If the assumption is right, then the style of defense that's taught is to focus on deflections and steals, which leads to more turnovers and fouls committed. The problem is that this benefit to our defense is not enough to overcome the negative implications from the extra fouls we commit. The extra trips to the free throw line for our opponent are worse for us than the times our opponent commits a turnover.

Furthermore, since conventional wisdom tells us teams protect the ball better in the post-season, does Marquette's defense get exposed even further? Our ability to force turnovers went way down last year in the post-season, but I'll have to do more analysis before saying the defensive strategy gets worse for MU.

If the assumption is wrong, then I can't blame the defensive strategy and emphasis on turnovers for the extra fouls committed. However, the fact remains that there is a significant impact on team performance from allowing our opponents to head to the free throw line so much. One thing is certain, no matter what the implications of the defensive strategy may be, the coaching staff needs to emphasize that we stop putting opponents on the free throw line so much.