Our first look at correlations between Effective Height and defending the paint was earlier this week. That post was inspired by another post from Tom Haberstroh at Hardwood Paroxysm comparing Effective Height to team rebounding rates. To recap, Haberstroh created the metric of Effective Height, which is the average height of a team with the heights of respective players weighted by the number of minutes they played. Haberstroh found moderate correlations between eHeight and Total and Offensive Rebound rates. I then took his eHeight numbers and compared them to a few team defensive categories: Block Rate, Opponents At Rim FG%, and the percentage of an opponents field goal attempts which came at the rim. I was surprised to find essentially no correlation between any of those categories and a team’s eHeight.

After seeing those results I wondered if the height contributions of a team’s backcourt might be muddying the correlation data. I then calculated the eHeight of each team using just their frontcourt players. To do this, I used the position designations from Basketball-Reference.  There were a lot of teams I didn’t see much of this season, and I didn’t feel comfortable using my own observations and opinions to assign positions to different players. I am sure some of these position designations are not entirely consistent with a player’s role on his team, but for the sake of consistency I stuck with them.

The first table shows the Frontcourt eHeight compared to Haberstroh’s numbers for each team’s eHeight. I also calculated the difference between the two. The higher the eHeight difference, than the smaller a backcourt the team played with this season. I also included the percentage of a team’s minutes which were played by frontcourt players.

I want to return the frontcourt minute percentage for each team for just a moment. A traditional basketball lineup features 2 forwards and 1 center, or 3 out of the 5 players. Therefore a minute distribution based on a traditional lineup would have exactly 60% of the minutes being played by frontcourt players. Looking at the numbers here it is easy to see the teams ascribe to the small ball movement. Teams like Houston and Orlando, who have true small forwards (Vince Carter and Trevor Ariza) playing a majority of their minutes at shooting guard, stand out as well.

The next table shows my Frontcourt eHeight calculations compared to team rebound rates. 

In each case the correlations which much weaker than they were Haberstroh’s team eHeight. I found this to be extremely surprising. Apparently, I have underestimated the rebounding contributions of a team’s backcourt. I also think it’s interesting that you can almost see the influences of individual players. Orlando and San Antonio don’t have particularly big front courts, but they do have Dwight Howard and Dejuan Blair.

The last table compares Frontcourt eHeight to those defensive categories I discussed earlier.

There was an increased correlation with Block Rate, but other than that the correlations were weaker than when using the eHeight of the entire team. Again this would seem to indicate that controlling dribble penetration and challenging shots, have just as much impact as length and height, in defending the paint. I am sure there is much more to this equation than my meager analysis has provided. With an eye towards the NBA Draft it might be wise for teams to focus on the skill set and motor of a player as opposed to falling in love with a physical profile.

Also seen at ilevy.wordpress.com

This post came dangerously close to being the second installment of my Random Number Generator series. In the end the numbers weren’t so much random as they were predictable and led to extremely obvious conclusions. I was very intrigued by Tom Haberstroh’s effective height post at Hardwood Paroxysm last week. One bit of minutiae that I loved was the way he color-coded his tables. Now that I have discovered this feature on Excel you can expect to see a lot more of it! I also discovered how to calculate statistical correlations with Excel, and have obviously gone a little overboard.

With my new found correlating and color-coding skills, I set out to examine the idea of Offensive Efficiency a little bit more. The three most efficient areas on the floor to score from are: at the rim, from the free throw line, and on three pointers. The two former increase efficiency because they present relatively easy scoring opportunities, while three pointers offer the bonus of an additional point per shot.

I created this table to see which of these areas has the greatest correlation with Offensive Efficiency. I included the FG% for each team at the rim, as well as what percentage of their shots were taken at the rim. The same data is included for three pointers. For free throws I included the percentage made and the average number of attempts per game.

Strong Correlations -

• Correlation between At Rim FG% and Offensive Efficiency:  0.663
• Correlation between 3PT% and Offensive Efficiency:  0.773

Low/Moderate Correlations -

• Correlation between 3PTA% and Offensive Efficiency:  0.399
• Correlation between FTA/g and Offensive Efficiency: 0.390

(Essentially) No Correlation -

• Correlation between FGA% At the Rim and Offensive Efficiency:  -0.075
• Correlation between FT% and Offensive Efficiency:  0.099

Obviously, At the Rim FG% and 3PT% had very strong correlations with Offensive Efficiency. I am not sure I really need to state this fact. If you make more of your shots, you will average more points per possession. Not sure I needed to state that one either. The categories with low or no correlations were much more surprising. You definitely need to make a high percentage of your shots at the rim to be efficient offensively, but apparently it doesn’t matter much how many shots you actually from that area of the floor. Also making a high percentage of your free throws isn’t nearly as important as attempting a lot of free throws. Good news for Dwight Howard! Stay tuned for the total lack of surprises in Part 2 of this post, when I put my coloring and correlating skills to the test with Defensive Efficiency.