After a discussion with WP48 expert Holland, I realized that I semi-botched my projection of the Cavs’ team performance this upcoming season. I wanted to take some time tonight to correct the analysis.
For those of you actually interested in advanced statistics, the main error involves some of the nuances of WP48. The purest form of the metric involves position adjustments. For example, a point guard’s WP48 performance isn’t weighted in exactly the same way as a center’s. Without adjusting, the metric heavily favors big men because they’re so much more likely to, say, get rebounds and shoot a higher percentage, as well as much less likely to turn the ball over (all important components of the entire scheme).
My source for WP48 was Basketball Reference, which is still a fantastic resource for advanced stats. However, if anyone out there wants to use it, keep in mind that the WP48 figures they give appear to be unadjusted.
OK, with the explanation out of the way, here are the adjusted WP48 totals for the roster hold-overs from last season. I kept all of the other parameters the same as in the original post.
Varejao = .181 WP48 x 36mpg x 82 games = 11.1 wins
Mo = .116 WP48 x 36mpg x 82 games = 7.1 wins
Moon = .191 WP48 x 36mpg x 82 games = 11.7 wins
Hickson = .123 WP48 x 20 mpg x 82 games = 4.2 wins
Gibson = .042 WP48 x 9 mpg x 82 games = 0.6 wins
Jamison = .194 WP48 x 36 mpg x 82 games = 11.9 wins
Parker = .081 WP48 x 36 mpg x 82 games = 5.0 wins
Powe = .000 WP48 x 9 mpg x 82 games = 0 wins
Green = .074 WP48 x 9 mpg x 82 games = 1.1 wins
Jawad = -.069 WP48 x 9 mpg x 82 games = -1.1 wins
Telfair = .020 WP48 x 4 mpg x 82 games = 0.1 wins
TOTAL PROJECTED WINS PRODUCED BY 2010-11 CAVS: 52 wins
So after adjusting for position, WP48 actually projects the Cavs to win one additional game beyond what the unadjusted numbers projected. This is mostly due to dramatically increased ratings for Moon and Jamison. Their gains more than offset significantly lower ratings for players like Mo, Gibson, Parker, Powe, and Jawad.
The other error I made in Monday’s post had to do with the expected error involved in the calculation.
I said at the time that WP48 predicted win totals to about 80% accuracy. I undershot. It’s actually (allegedly) accurate to within 94%. The error range is about +/- 1.5 games. Essentially, what this means is that the 2010-11 Cavs have a 94% chance of winning somewhere between 50.5 and 53.5 games.
Let me repeat that: if no changes are made to the current roster, and the rotation looks something like what I’ve outlined above, the Cavs allegedly have a 94% chance to win at least 50 games in their first season without LeBron. That’s +20 wins higher than what even the most optimistic sports pundit (that I’ve seen, anyway) has predicted for the team next season.
Of course, if Byron Scott chooses to start Jawad at 3 over Moon, this entire projection goes out the window. And I might, too. (Though I live on the first story, so the effect would probably be pretty muted.) But for now, things are definitely looking up.
Now, as I noted in my original post on this topic, I still think we’re running a significant risk in these projections if we only look at the numbers from last season. (Unfortunately, I don’t have adjusted career WP48 numbers.)
One of the points where I split with the WP48 philosophy has to do with synergy, for lack of a better term. The WP48 system assumes that player production is an inherent trait determined by the player’s skill level. In other words, he will produce roughly the same over time regardless of who the other 4 men on the court next to him are, not to mention who the 5 defending him are.
I, on the other hand, believe that a player’s teammates have a significant effect on what he’s capable of doing. For example, a spot-up 3-point shooter gets much better looks if he’s playing with someone on the front line who demands a double-team. Theoretically, he should be more open for his shots and should drain a higher percentage. I would argue that Mo Williams has been a great example of this. In his 2 seasons with the Cavs, he’s shot 43.6% 3P and 42.9% 3P, respectively. In the previous 4 seasons in which he’d played significant minutes with Milwaukee, his career high from beyond the arc was 38.5%. That’s a 4.5-5% uptick since starting next to LeBron.
This will be one of the elements to keep your eye on this coming season. Can the Cavs players find a way to do what they did with LeBron? As Mike pointed out, their current roster has a very low number of guys capable of creating shots for themselves. We’ll see how that affects things, along with the new up-tempo system Scott is already implementing in the Vegas Summer League. (Side note: WP48 disregards pace, so in theory this shouldn’t affect the projected win total. I remain skeptical on this point, but that’s a discussion for another day.)
That said, if things proceed as I expect, I still plan on checking into the over/under on Cleveland’s win total for 2010-11 if I’m in Vegas before the season starts.
All right, I think this is the last numbers-centric post I’m doing for a little while. Pseudo-philosophy, pseudo-psychology, and pseudo-humor back next week.
-T
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