Royals Review put together a very good post that defines the #1, #2, #3, #4 and #5 starters with various stats.  This is great because people often call a pitcher an “ace” or a “mid rotation guy” or whatever else, but what good does it do when everyone has a different idea of how to define a pitcher’s role? 

Seattle’s rotation was a mess this past season and various titles were given to each pitcher at different times.  I thought it would be interesting to use a watered down version of Royal Review’s system to slot the 2008 Mariners starting staff into defined roles, so head over to their site before continuing on.

Felix Hernandez – 1.5
Erik Bedard - 2.75
Carlos Silva – 4.25
Jarrod Washburn – 4.5

Based on the averages of where the starters landed in each stat category on Royal Review’s chart for 2008, Hernandez was the closest thing Seattle had to an ace, but wasn’t quite there.  The injured Bedard pitched like an above average middle of the rotation guy while Silva and Washburn landed about where expected– the back of the rotation.

(Unforunately I can’t find split data for advanced stats such as FIP, xFIP and tRA, and thus can’t put Ryan Rowland-Smith and Miguel Batista in this.  If anyone knows where these numbers can be found, that would be great of you to share!)

Anways, this shows that Seattle’s 2009 rotation should match up well against the MLB norm.  Felix was just a tenth of a point from being considered an ace this past season, so any progression will put him in that category.  If Bedard can stay healthy he has ace potential as well, meaning Seattle would have a better one-two punch than most teams.  If he is pitching through pain I would guess that he would still be a solid #2, but no worse than he was this past season.  I like to think that Silva will get healthy and his numbers will regress back towards the mean next season, which would put him somewhere between the solid #3 he’s been in the past and the passable four he was in 2008.

If Felix, Bedard and Silva can pitch like an average/above average #1, #2 and #3, all Rowland-Smith and Brandon Morrow have to do to make Seattle 2009 rotation a good one is to pitch like above average/average #4 and #5s, which is entirely possible and probable.  Now, Bedard and Silva  can slip all the way to their 2008 levels again and RRS and Morrow would still only have to pitch like a combined #3 and #4 in order to get the rotation back to league average.  Either scenario gives Seattle a better rotation than a lot of other teams, which is good news.  (This is obviously assuming that Washburn is traded, since there is no room for him and Silva would be much harder to move.  That said, I think Washburn could be kept as Bedard insurance until he proves he’s healthy.)

This post was kind of confusing, but the point is that Seattle’s rotation should stack up better than the average MLB rotation next season, which is a welcome edge considering the offense and defense will probably be below average.