Re: Athlon Sports on scoring efficiency

[Alexander Wang <awang@MIT.EDU>]

At 05:40 AM 10/25/01, Thomas Murphy wrote:
>During the '2nd half' both Paul and Ray were presented with each other's
>situations from the 'first half' - Paul got three dunks and two wide open 3s
>whereas the defense clamped down on Ray and he got one open look for 2 pts
>but otherwise was presented with four tough possessions which led him to
>pass the ball back to Sam Cassell. The final box score looked like this:
>Pierce 6-6 6-8 20 pts
>Allen 6-6 0-0 14 pts.
>Now according to your formula for efficiency Ray Allen is supposedly more
>efficient than Paul (2.3 to 2.0) despite having scored 6 less points in
>exactly the same number of possessions!

A couple of things here. When Ray passes off to Sam Cassell, his team 
doesn't lose possession of the ball, so this is fundamentally different 
from a scoring opportunity where the other team typically gets a defensive 
rebound.

Second, somehow Paul dunked the ball three times and hit two three pointers 
and his scoring efficiency dropped to a third of what it was. Isn't this a 
perfect indication of why PPS is flawed?

Much of your remaining arguments rest upon the "role player vs. star 
player" distinction. The star players have the responsibility to generate 
points in difficult situations where role players can pick their spots, 
which is why Steve Kerr is never going to be an All-Star. And most of these 
guys go to the line. This efficiency is not "washed out" as you say though, 
because FTs are converted at a much higher percentage (and when they're 
not, like when Rodman shoots 30%, it didn't really benefit the team very 
much).

Anyway, of course you have to separate these types of players; numbers 
won't give you everything. But lest you believe that the efficiency measure 
I proposed "logically" leads to ridiculous results (like Steve Kerr > MJ), 
let me propose my own example. Let's say that Ted is a 4'6" third-string 
point guard who has no offensive talent, but he can get open in inbounds 
plays, take care of the ball, and hit free throws. Ted's coach puts him in 
during late game situations when his team is up a few points, to take the 
intentional foul. So over the course of the season, Ted goes 18-20 from the 
line, all from intentional fouls. At the end of one game, Ted throws up a 
halfcourt shot for fun and misses it. So Ted's season efficiency score is 
based on 0-1 FG, 18-20 FT, for a PPS of 18! Obviously you wouldn't argue 
that Ted is far more efficient than Michael Jordan, just as I wouldn't 
argue that Steve Kerr is more efficient than MJ, even though Steve at least 
had to hit a couple of three pointers in a real game situation.

The main point is that there is a volume effect which isn't accounted for. 
Guys who convert at a higher volume are more valuable at the same 
efficiency level. But incorporating this volume effect into your formula by 
arguing "Higher volume requires free throws so let's boost up the value of 
free throws a ton" is invalid. In terms of efficiency, the relative 
efficiency of free throws vs field goals is accounted for by their higher 
percentage. That's why Pierce is still #2 by my measurement after Shaq. By 
"excluding" the attempt from your calculation, you're missing a fundamental 
point, which is that the other team gets the ball - you lose possession - 
always after a made FG or FT and most of the time off a missed one.

Anyway, the thing is that big time scorers who go to the line a lot and 
shoot high percentages still rate extremely highly under the measurement I 
proposed, with Pierce still #2 behind Shaq. I just think that you avoid 
some weird anomalies that PPS gives you, like Eric Williams behind roughly 
as efficient as Vince Carter. Eric's not as inefficient as his FG% says 
because he does go to the line a lot, but in my mind it makes him 
relatively average (which he is under pts/(FGA+FTA/2)) rather than very 
good as he is under PPS.

Alex