payitforward wrote:fishercob wrote:TheSecretWeapon wrote:Lemme try that again...
02-03 -- 66, 84, 21
03-04 -- 119, 134, 11
04-05 -- 136, 149, 9
05-06 -- 127, 115, 10
06-07 -- 138, 128, 8
07-08 -- 132, 133, 1
08-09 -- 117, 98, 19
09-10 -- 123, 91, 35
10-11 -- 104, 62, 68
11-12 -- 81, 48, 69
12-13 -- 84, 65, 29
13-14 -- 60, 38, 57
14-15 -- 81, 73, 11
So, just an interesting statistical exercise/observation given Ruz's skepticism off WS/48: I am putting Prince's WS/48 numbers in bold indexed to 100 next to your PPA measure, just to see how they stack up.
If you average the discrepancy between WS/48 and PPA over the first 7 season of Prince's career, there virtually is none -- which may be a coincidence, but it's quite interesting.
Then from 09-10 until last year, the average discrepancy was huge, like 38%. Kevin, any idea as to what's behind these phenomena?
I don't think averaging the discrepancies over multiple years is a valid step methodologically. The shape of the curve is pretty different, and the biggest discrepancies are in the prime of his career.
WS/48 has his year 2 as the second best year of his career. PPA has it as the 6th best (i.e. right in the middle). WS/48 has his year 5 as the peak of his productivity. WS/48 has it 4th best. And a number of year-pairs that PPA says are very close, WS/48 ranks as very different. Viz. 03-04 and 08-09, and 02-03 and 13-14.
At least one of the two metrics is bizarrely off, and if WS/48 refers to "Win Shares", my money is on that one.
Now adding percentage discrepancy between the two metrics in red.
I don't agree that the biggest discrepancies are in his his prime. Years two through six had a maximum discrepancy of 11%. Years 1-7 had a maximum discrepancy of 21% -- and keep in mind he only played 435 minutes as a rookie. But the discrepancy starts to get much larger as his production drops. Again, I don't understand why and don't know enough about how either metric is calculated to venture a guess. It's just an observation. But it would be helpful to understand why over the past 5 seasons, PPA says Prince is a average/below average player and WS/48 says pretty stinky.
By the way, I realize we're looking at a single player here and the data may look completely different when looking at dozens or hundreds of players.


















