nate33 wrote:When you posted the numbers of an "average PF", I assumed it was the numbers for all power forward minutes played by everybody, not the performance of the median PF in the league. Since starters play more than half of all PF minutes, a bad starter would be roughly an average overall PF.
It's the average of player performance. IOW, list all PFs & ask how many defensive rebounds did each of them get per x minutes. Then take all the numbers you get & find the average. Rinse & repeat for shots taken, points scored, assists, turnovers, etc.
Pretty standard way of proceeding. In fact, it's the only way of proceeding. That way, when I learn that player A gets 6 defensive boards per 40 minutes & player B gets 8, while player A gets 3 assists more than player B, I have data to try & figure out how those 2 difference affect my ability to win games playing one or the other guy.
Whereas, if I weight by minutes in the way you describe, so that I'm trying to find an overall average level of "play" -- as opposed to defining the output of an average "player" -- I don't have data for a metric that lets me pick players. IOW, the key problem in what you write below is that you treat "player goodness" as a known, when that's what we're trying to get to. That's the unknown we're trying to find.
IOW, we're trying to find out whether "Mike is a modestly below average overall PF." (Or, in another instance, whether Carmelo Anthony is as good a player as people think he is)
To do that, we have to understand what it means for e.g. one guy to be better at rebounding vs. another guy who lets say shoots a higher %. I.e., we have to figure out the value (or cost -- a negative number value) to each element of what a player does -- i.e. to a defensive rebound, an offensive rebound, an assist, an FGA, etc.
Obviously, the only way to do this is by running regressions on those data elements using SAS or other statistical software. Once you've worked that out, you have a way to know how good/bad Mike is. Or LeBron or Kieff or anyone. You create a roll-up that combines those disparate stats, at the numerical value of their impact, into a single # per 40 minutes (or 48 or 36 -- doesn't matter as long as it's consistent).
PER does that. Kevin Broom's PPA does that. WP48 does that. Of course, none of these are "the truth" in some absolute way. They're just tools. All you can do is measure them against actual wins & losses to see which correlates best over repeated use. That's what it means for one of them to be "better" or "truer" than another. Use the one that correlates best (duh). Of the previously mentioned, for example, PER correlates at the lowest level (because it doesn't penalize a player for taking lots of shots at a low FG%).
When we do that, we do not find that "Mike is a modestly below average overall PF." We find that he is a way way below average PF overall.
IOW, he is certainly "a detriment" if he's your backup PF. Of course, he may still be a bargain at a veteran minimum salary! That depends on something different -- who else is available at that price. But, he is not a guy you want to play 20 minutes a game! Not if you want to win a lot of games.
nate33 wrote:Here's another way of looking at it. There are 118,080 total minutes at the PF position in any season. (In reality, some percentage of those minutes are small ball where small forwards move into the PF position, so it's probably more like 100,000 minutes occupied by true power forwards playing the PF position.) The best PF in the league, Lebron James, played the 3000 best minutes at the position. The second best PF, Kevin Durant, played the next-best 2325 minutes. Once you go through the 20 or so best PF's you've already accounted for maybe 45000 minutes of those 100,000 total PF minutes. Now you look at the bottom level of starters, the worst 10 starting PF's in the league, and they fill up minutes 45,000 through 55,000. These are the guys playing "average PF" minutes since 50,000 is right in the middle of 100,000. So even a good backup would fall in the below average range among all PF minutes. So if Mike is a modestly below average overall PF, he still might well be a good backup, or at least an ordinary backup.
I'm not saying he's a great player. And I get your overall point that he's not as good as his scoring average and shooting percentage suggest since he doesn't fill up the box score. All I'm saying is that having a mildly below average PF as a backup isn't a detriment. It's normal. And to have him at a vet minimum salary is good.