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Behind the numbers (cont.)

Posted: Monday February 19, 2007 3:40PM; Updated: Monday February 19, 2007 3:43PM
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By David Appelman, Fangraphs.com

It's worth noting that ZiPS does not attempt to project playing time and of the four projection systems, it has the most players with 995 batters and 989 pitchers, many of whom have yet to play in the majors. So with at least a decent idea of the workings behind each projection system and their differences, let's take a look at how similar they are by comparing how they project OPS and ERA for individual players. Using the Marcels as a baseline since it's the simplest system of the four, if we look at batters with at least 300 at-bats in projected playing time, and pitchers with at least 100 innings in projected playing time, we'll see that the four systems are quite similar.

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Despite their similarities as a whole, there are a number of differences in the four systems if you look at any specific players. Here are the 10 batters the systems are in the least agreement with in terms of OPS:

Name Bill James OPS CHONE OPS Marcel OPS ZiPS OPS
Ryan Howard 1.101 0.980 0.996 1.024
Chris Duncan 0.862 0.776 0.891 0.803
Dioner Navarro 0.685 0.740 0.767 0.664
Luis Gonzalez 0.833 0.731 0.794 0.754
Dan Uggla 0.837 0.740 0.821 0.770
Esteban German 0.734 0.744 0.830 0.745
Eliezer Alfonzo 0.736 0.684 0.771 0.678
Carlos Delgado 0.931 0.840 0.900 0.855
Andre Ethier 0.833 0.754 0.841 0.829
Hector Luna 0.702 0.682 0.769 0.689

It's interesting to see Ryan Howard atop the list. Everyone expects him to be very good, but there's certainly some question about how great he'll actually be. At least CHONE and ZiPS seem to think Carlos Delgado is in for a rather steep decline next year, while the other two think he'll keep chugging along at his .900+ OPS.

But the problem with comparing OPS across projection systems, especially for the fantasy baseball players out there, is that it that it takes the systems out of their own context, which is why it might be more helpful to rank the players by OPS and see how their rankings compare. Once again, here are the 10 players the systems are in disagreement about in terms of ranking by OPS.

Name Bill James CHONE Marcel ZiPS Average
Esteban German 209 193 77 176 163.75
Daniel Uggla 77 201 87 155 130
Andre Ethier 85 177 62 64 97
Luis Gonzalez 83 208 135 168 148.5
Jose Vidro 111 118 191 202 155.5
Bengie Molina 206 104 178 196 171
Chris Duncan 51 126 24 99 75
Coco Crisp 188 102 155 92 134.25
Shawn Green 103 205 129 171 152
Howard Kendrick 76 90 169 148 120.75

A few of the same names show up on this list like Dan Uggla, Andre Ethier, Luis Gonzalez, Esteban German, and Chris Duncan, but you'll notice it devoid of Howard. Despite the systems not agreeing on his actual OPS, they all agree that he'll have one of the top OPSes in all of baseball:

Name Bill James CHONE Marcel ZiPS Avg Rank
Albert Pujols 1 1 1 1 1
Brad Ausmus 254 254 254 254 254
Lance Berkman 5 6 6 6 5.75
Travis Hafner 4 2 2 3 2.75
Mark DeRosa 201 203 200 201 201.25
Grady Sizemore 31 30 32 33 31.5
Ryan Howard 2 5 3 2 3
Adam Everett 249 251 252 252 251
Mark Teixeira 16 13 13 15 14.25
Juan Rivera 67 64 67 67 66.25

Moving on to the pitchers and their projected ERA, you'll remember that overall there was a bit more disagreement between the systems for pitchers and ERA than there was with batters and OPS. Pitchers are quite a bit more unpredictable than batters. So let's see where the systems are in disagreement:

Name Bill James CHONE Marcel ZiPS
Orlando Hernandez 4.14 3.77 4.82 4.65
Rich Hill 3.40 3.65 4.46 3.65
Tim Wakefield 4.14 4.30 4.74 5.16
Odalis Perez 3.93 4.63 5.00 4.75
Oliver Perez 5.03 4.14 5.10 4.5
Mark Redman 4.40 5.05 5.20 5.32
Wandy Rodriguez 5.60 4.64 5.20 5.07
Boof Bonser 4.22 4.02 4.42 4.94
Clay Hensley 3.28 4.05 3.71 4.14
Curt Schilling 3.50 3.94 4.45 3.98

A few names stand out to me here, mainly Rich Hill and Curt Schilling. The Handbook takes the low road on both of them, with the Marcels not being quite so optimistic. With only one year of major-league playing time for Hill, there's going to be some heavy regression for the Marcel projection. The Handbook is also quite smitten with Clay Hensley. I can only image it has something to do with him playing in PETCO park and his extreme groundball tendencies. Let's take a look at where the projections are in agreement:

Name Bill James CHONE Marcel ZiPS
Carlos Zambrano 3.48 3.47 3.48 3.46
Bronson Arroyo 3.93 3.90 3.98 3.86
Dontrelle Willis 3.77 3.92 3.83 3.77
C.C. Sabathia 3.67 3.60 3.78 3.61
Aaron Harang 4.15 4.01 4.18 4.03
Kirk Saarloos 4.97 4.98 4.79 4.98
Nate Robertson 4.40 4.25 4.40 4.21
Gil Meche 4.76 4.66 4.77 4.9
Kelvim Escobar 3.89 3.68 3.90 3.79
Scott Kazmir 3.68 3.63 3.81 3.57

It's interesting to see such agreement on Bronson Arroyo considering he's had exactly one year with an ERA under 4.00. Obviously, C.C. Sabathia and Carlos Zambrano have had a much better long-term track record and it shows in both their projected ERA. It's also fun to see that everyone agrees Kirk Saarloos and Gil Meche are nothing to write home about. But where are Johan Santana and Roger Clemens? Let's take a look at one last list that shows which player each projection system is in agreement on in terms of ranking by ERA:

Name Bill James CHONE Marcel ZiPS Avg Rank
Runelvys Hernandez 126 128 128 128 127.5
Roy Oswalt 7 5 8 6 6.5
Johan Santana 1 1 1 4 1.75
Jered Weaver 3 7 6 3 4.75
Tony Armas Jr. 106 104 110 104 106
Brian Moehler 127 121 127 124 124.75
Ramon Ortiz 123 119 126 121 122.25
Jake Peavy 10 3 9 8 7.5
Carlos Zambrano 13 8 5 9 8.75
Roger Clemens 2 9 2 1 3.5

Santana is nearly a consensus number one. Jake Peavy and Roy Oswalt also make high appearances in each system, while Runelvys Hernandez, Tony Armas Jr., and Ramon Ortiz are not so highly thought of.

So whatever projection system you're inclined to use, regardless if it's actually better or worse than either of these four, it's probably similar as a whole yet with its own nuances. A second opinion never hurts, and if you head over to FanGraphs, you'll find four other opinions at your disposal.

David Appelman is the creator of FanGraphs.com He can be contacted via e-mail at david@fangraphs.com

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