Monday, June 23, 2008

Advanced Statistics and the Portland Trailblazers Pt. II

I was going to start writing this post a couple of days ago, but I had a little bit of trouble coming by the numbers that I needed. Pace and efficiency stats aren't too tough to come by, but the other numbers are. Well, they are in the form I wanted them in. 82games.com (which is awesome for other reasons...) has the rebounding numbers, but only to 2 decimal places. To really compare across the whole league, the third decimal is important. So, I wound up building a spreadsheet and calculating the numbers by hand. That was before I found the table I was looking for on basketball-reference. I got lazy when it came to calculating league averages for pace and efficiency. I am sure you will cope. Well, with that out of the way, here are the numbers.


Portland League Rank League Leader League Worst League Average
Pace 89.7 29 99.7 (Denver) 87.3 (Detroit) Not Available
Offensive Efficiency 107.3 14 113.8 (Utah) 100.5 (Seattle) Not Available
Defensive Efficiency 108.4 17 98.9 (Boston 112.8 (Milwaukee) Not Available
eFG% 49.00% 16 55.2% (Phoenix) 44.3% (Miami) 49.30%
oReb% 26.70% 15 31.8% (Philadelphia) 22.1% (Miami) 26.70%
dReb% 71.80% 24 .783 (LA Clippers) 70.3% (Golden State) 73.40%
TO% 13.40% 7 11.4% (Toronto & Detroit) 16.5% (Boston) 13.00%
FT Rate 22.80% 21 27.6% (Sacramento) 18.3% (Minnesota) 23.20%

Alright, so there are the numbers. What do they mean? That is a good question. And it is a question that doesn't have an easy answer.

First, looking at pace we see something that I think we knew intuitively. Specifically Portland plays slow, deliberate basketball. Moreover, I don't see that changing a whole lot as long as B. Roy is around. But we also see that Portland is pretty efficient on the offensive end. And efficiency is the important thing.

The defensive end is another story. And, to further illustrate why pace independent statistics are important, if we look solely at opp points/game, Portland is 8th in the league. But once we take Portland snail like pace into account, we see that rather than in the top 1/3 of the league, the Blazers are really in the bottom half. I also think it is important to note that although Portland is near the middle of the league in Defensive Efficiency ranking wise, the distance between Portland and Milwaukee is pretty small.

The other two numbers that really jump out are defensive rebounding and FT Rate. I think most people recognized that Portland struggled on the defensive glass this year. This is an area Portland should look to improve on. With the addition of Oden in the middle, I am expecting some strong improvement here. A better dReb% should also help improve Defensive Efficiency. It is pretty easy to see the strength of keeping an opponent of the offensive glass.

I am less sure what to make the FT Rate numbers. Of the Four Factors, this one is generally regarded as the least important. Also, although ranked quite low, it appears there is a big bunch near the midpoint, and Portland isn't far from it. Looking at the numbers behind Portland's FT Rate, the Blazes made their foul shots at a good clip (about 76.6%), but really didn't get to the line that often. If Portland had gotten to the line as often as the league average, they would have scored almost 1.34 more points per game. Is that much of a difference? It is worth about 4 wins under the basketball Pythagorean formula*. I would say that is fairly significant.

So, did any of this really communicate information that wasn't clear to somebody just watching the season? I am sure some of it was clear. But if you didn't dig into these numbers, you may think that Portland didn't have much trouble on defense, or that the lack of defensive rebounding wasn't particularly crucial. Either of those beliefs could lead to bad moves as it comes time to build the team for next year.

*In case you are not familiar with it, one of the first big advances in sports statistical research was the so called Pythagorean Theorem of Baseball, or Pythagorean Records. It seems almost a truism to say that your win/lose record is going to be determined by the number of runs(or points) you score and the number you give up. However, a little research showed that a teams winning percentage in baseball is closely tied to: runs scored^2/(runs scored^2 + runs allowed^2). It turns out if we tweak the exponent a little we get an even better fit. The same can be said for NBA Basketball. The generally agreed upon formula for basketball is: Pythagorean Expectation % = Tm pts^14/(Tm pts^14+Opp pts^14).

It should be noted that Portland exceeded it's Pythagorean Expectation this year by about 3 wins. Anecdotally it would seem this would be due to performing better then expected in close games, and losing a few more blow-outs then they won. I haven't taken the time to examine this, and I won't now as this post is getting a bit long.

3 comments:

Rip Tatermen said...

That is some crazy stuff. Seems to mesh with my memories of the season: a few games where we lost 'cause no matter how well we did with the ball, we couldn't stop the other team from scoring.
Are you jazzed for draft day? 'Cause I'm jazzed for draft day. I expect crazy-ass trade magic from KP.

Sydney said...

So how do you use these magical "stay-tees-ticks" of which you speak to determine the impact of individual players? Or maybe you don't. Is that done anymore? Or has everyone given up on the idea that you can parse an individual's performance in team sports? I know it's very hard in football to determine whether or not the quarterback is very good, the left tackle is very good, the coaching staff simply did very well at creating an offense that uses the most of limited players, or if the offense sucked. Woo "The Blind Side!" I sound like I know something about sports! Actually, at this point, I've seen enough PTI and listened to enough Blazers and Ducks games to understand quite a bit these days. But not hockey. Never hockey. Or baseball.

Beau said...

You could say I was jazzed for draft day. KP is like a crazy crazy god.

Syd, only Canadians understand hockey, and I think its mostly just ice and bloody fights for them. As for these "statistics," these posts have focused on measures of the team as as whole. There could be several more posts about what is going on with individual statistics etc.