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Diamond Dope - RC/27 v BR v NERP

PostPosted: Wed May 30, 2012 7:50 pm
by novie
When evaluating players value, wondering how others view the importance/difference between the three measurements and which measurements should be given more weight depending upon batting order placement (say leadoff vs run producing spot) as well as ballpark type (pitcher, neutral, hitters... having already added in BP effects)?

As well, how do you view those difference for starters as well as relievers?

PostPosted: Thu May 31, 2012 11:07 am
by Valen
Mostly a tossup between the 3 on deciding which players to have on team. A player who is tops in one is usually tops in the others as well.

As to determining lineup order completely ignore them. Tend to focus more on other stats that I consider relevant to batting order position. The typical desire for high OBP in first 2 place setter slots with slugging in middle of the order for run production.

PostPosted: Thu May 31, 2012 1:34 pm
by ADRIANGABRIEL
Well, RC/27 says that 1906 Ed Reulbach is a better pitcher than 1915 Pete Alexander so take that for what it's worth...

BR and NERP are both based on linear weights, but NERP also factors in gbAs and can be combined with [url=http://www.mfooz.com/bblog/wp-content/uploads/offense-vs-defense.pdf]DeanTSC's defensive ratings[/url].

PostPosted: Thu May 31, 2012 2:01 pm
by novie
AG.... would you say that BB/HBP are given more weight in either RC vs BR or the other?

PostPosted: Thu May 31, 2012 2:56 pm
by ADRIANGABRIEL
I'm thinking BB/HBP are probably given less weight in the BR/NERP calculation because they are only valued at .33 of a run. Whereas RC is Total Bases x OBP, so BB and HBP--in the OBP calc--are given equal weight to hits.

PostPosted: Thu May 31, 2012 5:15 pm
by Outta Leftfield
My sense is that in order of accuracy the three measures are, from best to worst, NERP, then BR, then RC/27. Each has its uses, however.

The main advantage of RC/27 is that it's a quick and easy, do-it-yourself formula. It's pretty good accurate for such a simple stat, and its easy to understand, since RC/27 means the runs created using 27 outs, so in effect it puts a runs-per-game value on a player. But--as Bill James, it's inventor, has admitted--in its simple version it tends to exaggerate offensive values at the extreme high end of OBP and SLG, and that high end is where a lot of ATG6 happens, so it's not entirely reliable in this environment. Great as Babe Ruth is, he's not going to hit quite as well as RC/27 says he will. Plus it leaves out things like steals, DP, and other factors that might be important if they represent a real strength or weakness of the player.

Also, I think RC/27 tends to be overly kind to pitchers who walk a lot of people but don't give up many hits. Ryne Duren (.92M) is not really as good as he looks from the standpoint of RC/27.

So, I would lean toward the more sophisticated measures of BR or NERP. I think I understand the mechanics of BR a little better, but as Adrian says, NERP can be used with DeanTSC's defensive ratings to get a sense of the overall value of a player.

All 3 have their uses, but I would put the least trust in RC/27, especially when evaluating superstar players or players with special skills or weaknesses like SB or DP.

PostPosted: Fri Jun 01, 2012 10:23 am
by ADRIANGABRIEL
My preferred quick and dirty measure of a card is/was Total Bases + BB + HBP.

There is additonal information on the [url=http://diamonddope.com/help.cfm]Diamond Dope help page[/url].