Friday, November 30, 2007

AL Rotations by ERA for 2007

EDIT: Upon further review, I don't like the way I originally came about these numbers. For some reason, I had simply averaged each team's FIP in each spot for the league numbers. A smarter way to do it would be to treat the entire league as one giant rotation and determine the top 20% of starts (generally around 518 for the NL and 454 for the AL) for spot #1, etc. It makes no sense to penalize the league average rotation because the top 15 pitchers are clustered on, say, 8 teams. This tends to lower the value for #1 starters and raise the value for #5 starters while leaving the middle guys generally unchanged. I've changed the numbers in the tables to reflect the new method. The "average" rotations at the end are the same as before. Sorry for the mistake.

This post is similar to the last one using FIP. Using the ERA for each team's starters in games they started, I took the top 33 starts to determine the ERA for the #1 spot in the rotation, then the next 33 for spot #2, the next 32 for spot #3, the next 32 for spot #4, and the final 32 to find the #5 spot ERA for each team and then averaged those across all teams to get the league numbers. The STDEV column again gives an idea of how "even" a team's rotation was across all spots.

2007 AL Rotations and Rotation Spots by ERA

Cleveland Indians4.
Boston Red Sox4.213.143.884.424.755.150.78
Los Angeles Angels4.223.003.423.974.986.191.29
Toronto Blue Jays4.243.723.773.884.146.421.15
Oakland Athletics4.292.983.774.114.527.241.62
Minnesota Twins4.333.334.004.244.695.620.85
Chicago White Sox4.473.513.774.285.385.770.99
New York Yankees4.573.524.
Detroit Tigers4.683.474.574.824.995.930.88
Baltimore Orioles4.863.203.654.915.609.042.31
Kansas City Royals4.873.653.824.535.607.881.73
Seattle Mariners5.163.964.314.455.997.951.66
Tampa Bay Devil Rays5.203.483.905.785.967.751.73
Texas Rangers5.504.455.115.335.707.060.97

Despite the traditional thought that moving to the AL entails an increase in ERA, American League starters managed to post an ERA that was 0.03 lower than their NL counterparts (click here for the NL data in a new window). The American League total ERA was a little bit higher, but that was because AL relievers weren't quite as good as NL relievers, at least in terms of ERA. Interestingly, the #1 starters in each league came out to a 3.46 ERA. The #3 starters' ERA was also the same and the other three spots were very close.

Now to give the numbers context by seeing which pitchers fit in each spot:

AL #1 Starters (~3.46 ERA or below), 20+ starts
  • John Lackey, 33 starts, 3.01 ERA
  • Fausto Carmona, 32, 3.06
  • Dan Haren, 34, 3.07
  • Erik Bedard, 28, 3.16
  • C.C. Sabathia, 34, 3.21
  • Josh Beckett, 30, 3.27
  • Johan Santana, 33, 3.33
  • Jeremy Guthrie, 26, 3.44
  • Scott Kazmir, 34, 3.48 (it didn't feel right to exclude him since the next 20+ game starter had a 3.63 ERA)
AL #2 Starters (~3.95 ERA), 20+ starts
  • Brian Bannister, 27 starts, 3.87 ERA
  • Curt Schilling, 24, 3.87
  • Shaun Marcum, 25, 3.91
  • Jered Weaver, 28, 3.91
  • Felix Hernandez, 30, 3.92
  • Joe Blanton, 34, 3.95
  • Dustin McGowan, 27, 4.08
  • Andy Pettitte, 34, 4.09
AL #3 Starters (~4.52 ERA), 20+ starts
  • Daisuke Matsuzaka, 32 starts, 4.40 ERA
  • Chad Gaudin, 34, 4.42
  • Steve Trachsel, 25, 4.48
  • Paul Byrd, 31, 4.59
AL #4 Starters (~5.14 ERA), 20+ starts
  • Jeremy Bonderman, 28 starts, 5.01 ERA
  • Mike Mussina, 27, 5.16
  • Kevin Millwood, 31, 5.16
  • Julian Tavarez, 23, 5.22
AL #5 Starters (~6.81 ERA), 15+ starts
  • Cliff Lee, 16 starts, 6.38 ERA
  • Bartolo Colon, 18, 6.41
  • Robinson Tejeda, 19, 6.61
  • Horacio Ramirez, 20, 7.16
Not really any surprises, though it is worth noting the Orioles actually had two ace-level pitchers and a #3 pitcher, but not much else (see their #5 ERA above). The Mike Mussina-Chris Capuano analogy from yesterday seems pretty apt, since Capuano was also a #2 in FIP but fell to #4 in ERA.

I'll finish this up, as I did yesterday, with a recap of the "league average" rotation:
  1. Jeremy Guthrie/Scott Kazmir
  2. Joe Blanton
  3. Steve Trachsel
  4. Mike Mussina/Kevin Millwood
  5. Robinson Tejeda

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