Pat Riley's Magical Defensive Statistics

Last night during TNT's broadcast of the Heat vs. Cavaliers, David Aldridge talked for a minute or two about some kind of fancy system the Heat have developed to rank their own effort on defense.

Ok, fine, whatever, I imagine every team has some kind of system like that.

But then Aldridge tossed out some ridiculous numbers that Riley had told him. Essentially, when the Heat score very well in this system, they are undefeated. When they score pretty well, they almost never lose. And when they score poorly, they almost always lose.

Making it perhaps the most effective single basketball statistic I have ever known about.

A minute or two was not long enough to satiate my curiosity, so I got in touch with Aldridge today to try to find out a little more. Here's our exchange:

How did you learn about this?
I've heard that Riley has kept these really esoteric defensive stats for years (he was the first coach I know of that charted deflections, but he's been doing that since the Knicks days), but it's like pulling teeth to get him to cop to any specifics. Then last year in the playoffs he talked a little more about it, how they'd really fallen off in their defensive effort, down into the 60s (and we know anything under 70 is almost certain death for them).

I don't think the concept itself is a secret or anything; he's been doing it for a while. They take, I think, 25 categories (closing out on shooters, sinking to help in the post, deflections, rotating correctly, deflections, etc.) and grade the players. They then combine that with more traditional defensive stats to get their "effort index," if you will. But I don't think anyone had broken down the numbers before. He didn't go into greater detail, as he never likes to get too specific.

He said that Jeff Van Gundy had put a similar system in with the Knicks and Rockets, as did Stan Van Gundy when he was in Miami, but each tweaked it with his own categories.

Who charts all that?
The assistants chart it. That's why he's got five guys back there. I don't know how they break them down, but Spoelstra, McAdoo and Askins are the chief number crunchers. I think.

The numbers you cited on TNT were ridiculous -- almost like the holy grail of basketball statistics. When the D numbers are good, the Heat win. Period. Makes you wonder why we fuss over other numbers so much -- clearly they're secondary.
According to Riley (this was before the Cavs game), they haven't lost this season when they're at 73.9 or higher. When they're between 71 and 73 he said they're 31-5. When they're under 70 they're 3-22. Since they were 40-34 before the tip, I guess we can figure they got to 73.9 six times. The other seven losses? Don't know where they go; maybe they were under 60 a few times (like the season opener).