Comments on: So, Who’s This “Replacement Player” I Keep Hearing About, Anyway?

By: Neil Paine

Neil Paine — Tue, 31 Mar 2009 19:57:07 +0000

That's a good piece, Kevin, I hadn't seen that before. I guess this calls for a study of what PER your typical minimum-salary player is able to put up...

By: Kevin Pelton

Kevin Pelton — Tue, 31 Mar 2009 18:26:30 +0000

Rashad, the problem is that average players aren't easy to find. They create value for their teams by playing instead of replacement-level players. A metric that measures players against average doesn't give them the credit they deserve.

Neil, it's my opinion that the D-League standard is a little too low for what freely-available talent really means. Training-camp invitees or pretty much anyone playing for the minimum would seem to be freely available to me. That's the standard I used in my replacement level manifesto several years ago:
http://web.archive.org/web/20040325075607/http://www.hoopsworld.com/article_7557.shtml

By: Neil Paine

Neil Paine — Tue, 31 Mar 2009 18:12:21 +0000

I suppose that's true, Kevin. Head's performance in Miami has been much better than what you'd expect to get from a replacement, but he was pretty close to the replacement level in Houston, and Diawara's really right on it. Then again, both players have seen some significant playing time in their careers -- this year, it's especially been Diawara despite his performance (which, granted, was better last year). That's why I felt they were a notch above pure D-League-level players, because if they were that bad, you'd think they'd see fewer minutes.

By: Rashad

Rashad — Tue, 31 Mar 2009 17:34:20 +0000

I don't see the problem comparing people to the average. You won't get a value over replacement, you'll get a "how far does someone deviate from the average" stat, but that seems quite useful to know. Alternately, you could go down a standard deviation from the average if you want a lower-performing baseline. Also, basing it on standard deviations would be a pretty intuitive way to look at just what the number means. Of course, I don't know what the distribution looks like in the NBA. Probably has a wicked tail at the top end with the Lebrons, Chris Pauls, Dwight Howards, and Wades of the world sticking out like a sore thumb.

By: Kevin Pelton

Kevin Pelton — Tue, 31 Mar 2009 17:32:23 +0000

Neil, I would say by the time you get down to Luther Head and Yakhouba Diawara you're already getting into replacement-level talent. Diawara was signed for a little over the minimum and Head, after he was waived by the Rockets, is surely making the minimum. That makes them pretty freely-available too.

By: Jason

Jason — Tue, 31 Mar 2009 16:39:31 +0000

I actually emailed JH about this the other day. My problem with value over replacement player is that your not replacing LeBron with the 12th guy on the bench if he gets hurt. You are definitely not replacing him with an NBDL type talent. I like the idea of chaining based on the depth chart. Perhaps look at something like Value over First Replacement (VOFRP) which could average all of the first guys on the depth chart at that position (i.e. the theoretical replacements for a starter if they go down). I do think it's also true that as long as the methodology is consistent, the baseline for the comparisons will be similar.

If you wanted to take it another step, you could simply determine a league average Value Added and a league average value added by position and measure VORP based on that as opposed to using the 12th guy on the bench as a proxy. I suspect that the rankings will be similar regardless (guys like Kobe, D Wade, and LeBron are going to look great on this regardless of how its calculated. Their just good)!

By: Neil Paine

Neil Paine — Tue, 31 Mar 2009 15:46:49 +0000

How high/low you set the replacement level can matter a lot in that trade-off between counting stats and rate stats, though. Generally, the lower you set the R.L., the more you're going to emphasize counting stats -- which makes sense, given that counting stats technically have a "replacement level" of absolute zero. Conversely, the higher you set the level, the more you emphasize the player's rate of production (for instance, setting average = 0 considers everyone below average to have negative value). And if you took it to some really absurd length like "Value Over Kobe Bryant" or something, practically everyone in the NBA would be negative, how much would just depend on how close your rate was to Kobe's.

By: Jason J

Jason J — Tue, 31 Mar 2009 13:45:16 +0000

For a metric like Hollinger's PER, how much does the accuracy of the replacement level really matter? As long as it is calculated the same way every season, won't it give the same baseline for the comparisons to work and keep the number range the same? I guess it boils down to an "accuracy" vs. "precision" argument. Go high school science! Of course if the numbers could be both precise and accurate that would be great, but for the purpose of the advanced stats that use it, I would think that consistency would outweigh exactness. I do think you've got a helluva good point with the fact that it's so hard to determine definitive positions and even true starter quality. Guys like Manu & Terry, who are clearly among the top 3 or 4 players on the team, are going to skew things in a way that baseball (at least the position players in baseball) doesn't have to deal with. And even some great players are difficult to classify by position. Tim Duncan comes to mind immediately.