Aggregation of Fielding Measures

Over the last few weeks, I have presented several different fielding range metrics. I have placed all these articles in the fielding category on the side bar so that they can be easily referenced. The measures include range factor (RF), zone rating (ZR) and Chris Dial’s translation of zone rating into runs saved, Probabilistic Model of Range (PMR), Clay Davenport’s Fielding Translation (DFT), the Fan Fielding Survey, and the Fielding Bible Awards.

Two other respected measures – Ultimate Zone Rating (UZR) and the Fielding Bible Plus/Minus system (not to be confused with the Fielding Bible Awards) have not been discussed for individual players as the data are not available this year. UZR is summarized in an article written for The Hardball Times by David Gassko. The Plus/Minus system is discussed in an article at The Baseball Graphs Blog written by Dave Studenmund.

Fielding metrics are not yet as reliable as hitting metrics but much progress has been made in the elusive measurement of fielding performance in the past several years. I think we can generally say that players who do well on all of the metrics are good fielders and that players who do poorly on all of the metrics are below average fielders. However, there is a lot of variation across measures.

So, rather than rely on just one measure, I thought it might be a good idea to get an aggregate measure which combines all the individual measures. I am eliminating range factor from my aggregate because, although it’s a good baseline measure, I think it has too many holes to be a good summary of fielding performance. That leaves us with 4 measures for which data are available: ZR, PMR, DFT (specifically Fielding Runs Above Average) and the Fielding Bible Awards (of which the Fan Fielding Survey is a subset). The Fielding Bible Awards measure is different from the others in that it is subjective. However, I think that subjective evaluation is important in painting a complete picture of fielding performance.

This is how my system works: For each position, I ranked each player on each of the four measures and then calculated an average rank (which I call Average Fielding Rank or AFR). For example, Brandon Inge ranked 2nd among Major League third basemen in ZR, 6th in PMR, 2nd in DFT and 5th in the fielding Bible Awards. This comes out to an AFR of 4.

The benefit of this system is that if one of the measures doesn't work for a particular player, that one "bad rank" will be tempered by ranks on other measures. I used a straight arithmetic average in this example but one could easily use a weighted average if if it was thought some measures were more reliable than others. I’ll keep it simple for now. I won’t give the ranks for the individual methods for all the players because the Fielding Bible Awards are proprietary. I will, however, give a best ranking, a worst ranking and an average.

Table 1 below lists the 30 third basemen with 600 or more innings played in 2006. The table shows that Brandon Inge and Joe Crede tied for the best Average Fielding Rank in baseball. Pedro Feliz and Freddie Sanchez tied for 3rd at 5.5. The worst average rank (25) belonged to Alex Rodriguez.

Other positions can be found at the following links:

C 1B 2B SS LF CF RF

Table 1: Average Fielding Rank for Third Basemen in 2006

Player	Team	GP	Innings	Best Rank	Worst Rank	AFR
Crede	CWS	149	1260	1	11	4.00
Inge	Det	159	1392	2	6	4.00
Feliz	SF	159	1372	3	8	5.50
Sanchez	Pit	99	822	2	8	5.50
Beltre	Sea	155	1358	1	9	5.75
Rolen	StL	142	1216	1	8	5.75
Lowell	Bos	153	1299	4	10	6.00
Ensberg	Hou	117	975	3	15	10.00
Chavez	Oak	134	1166	4	19	10.25
Koskie	Mil	70	603	1	18	10.25
Zimmerman	Was	157	1368	8	13	10.50
Bell	Mil/Phi	143	1216	10	13	11.75
Tracy	Ari	147	1278	3	18	12.75
Punto	Min	89	766	7	19	13.00
Wright	NYM	153	1365	10	22	16.00
Nunez	Phi	74	632	10	24	17.00
Cabrera	Fla	157	1334	15	24	18.00
Izturis	LAA	87	707	4	25	18.00
Glaus	Tor	145	1175	11	27	18.75
Ramirez	ChC	156	1353	16	22	19.25
Betemit	Atl/LA	79	602	15	26	20.00
Teahen	KC	109	924	10	30	20.00
Blalock	Tex	122	1063	17	28	20.25
Jones	Atl	105	888	18	26	21.75
Huff	Hou/TB	90	700	18	29	22.00
Atkins	Col	157	1381	17	27	22.25
Mora	Bal	154	1323	18	30	22.25
Boone	Cle	101	842	16	30	24.00
Encarnacion	Cin	111	931	18	28	24.25
Rodriguez	NYY	151	1288	17	29	25.00