Defensive Ratings: Prepare for Surprises

Posted by Hayes Davenport on Jan 18, 2011 1496520 commentshttp%3A%2F%2Fcelticshub.com%2F2011%2F01%2F18%2Fdefensive-ratings-prepare-for-surprises%2FDefensive+Ratings%3A+Prepare+for+Surprises2011-01-18+15%3A45%3A00Hayes+Davenporthttp%3A%2F%2Fcelticshub.com%2F%3Fp%3D14965

Here’s something from the superfun but boringly designed Basketball Value’s database of five-man units. Something weird.

There are about 80 5-man units in the NBA that have played at least 90 minutes together (that’s a completely arbitrary time cutoff I made up). Some teams only have one unit with that much floor time (like New Orleans, where the starting lineup has played a quietly shocking 716 minutes). Boston has five such units, as one might expect from a team that has received several midnight visits from Injury Claus this season.

One of those five Boston units is number-one in Defensive Rating among the members of that arbitrary minutes category I made up. That means that unit held its opponents to the fewest points per possession in its time on the floor, basically. It’s the same as the Defensive Efficiency stat we usually refer to here, but on BV they use Rating instead. Anyway, none of this is surprising given that the Celtics are indisputably one of the league’s top 3 defensive teams.

But quickly guess which Celtics unit that is. I’ll put the jump here to make this marginally more interesting.

Wrong, probably. It’s Kevin Garnett, Paul Pierce, Ray Allen, Glen Davis, and Nate Robinson. I arranged those names for effect, which I’m sure you felt.

Also among those five Boston units is the second-best lineup in DR among all units with at least 90 minutes played. Go ahead and guess again.

It’s Kevin Garnett, Paul Pierce, Ray Allen, Shaquille O’Neal, and Nate Robinson. Those are your numbers 1 and 2 high-usage lineups in Defensive Rating this season.

I hear ya, kid. Hard to believe that a guy who consistently gives up five or more inches to the guy he’s guarding and who was benched about a year ago for not playing defense by Mike D’Antoni!!! would have a spot in the top two defensive heavy-minute lineups in the NBA. But there he is. Just chilling there in that list of names.

Conspicuously absent, meanwhile, is the reigning point guard of the league’s All-Defense first team.

The individual Defensive Rating statistic bears the weirdness out, however: Nate’s defensive rating of 101.3 beats Rondo’s of 101.88. They both make the team a little worse defensively when they’re on the floor, but Rondo makes the team more worser: the team’s DR is 2.8 points worse when Rondo’s on the floor, and only 1.03 worse with Nate.

Does that make Nate Robinson a more valuable commodity than Rajon Rondo, even from the perspective of these rating stats? Noooooo. Nonono. No. Because Rondo boosts the C’s offensive rating by 10.83 points when he’s in the game. That’s the 13th-highest increase in the NBA (number 5, notably, is your captain Paul Pierce with a net increase of 14.72). Rondo is better than Nate and it ain’t close.

But, for whatever reason, the Celtics are playing better defense when Nate’s in the game. Better than pretty much anyone.