How do you measure pitching?  There was some controversy when the Cy Young went to Colon.  Some felt just because of his W-L record.  since the pitcher has no control over the amount of runs his team scores, it makes sense to rate pitchers by what they can (to a degree) control.  The runs the opposition scores.  aka ERA.

I will just try to make the analysis simple.  There are 14 AL teams.  (I elimiated the NL teams because of the DH)  It makes a fair argument to say that the top 14 pitchers in the AL according to ERA are indeed the top 14 pitchers.  It stands to reason then that the next 14 pitchers are the second best.  

The following is a listing of the AL starting pitchers (not just a reliever who got a few starts) ranked according to ERA, and separated into groups of 14.                                                                                                                                  

Halladay  Tor  2.41
Harden    Oak  2.53
Hernandez Sea
Chacon    NYY
Millwood  Cle
Santana   Minn
Buehrle   CHW
Washburn   LAA
Baker     Minn
Silva     Minn
Lackey    LAA
Rodgers   Tex
Colon     LAA
Garland   CHW

Blanton   Oak  3.53
Contreras CHW
Towers    Tor
Chacin    Tor
Haren     Oak  3.73
Byrd      LAA
Kazmir    TB
Lee       Cle
Johnson   NYY
Chen      Bal
Zito      Oak   3.86
Garcia    CHW
Badard    Bal
Wang      NYY

Sabathia  Cle
McCarthy  CHW
Radke     Minn
Wakefield Bos
Saarloos  Oak  4.17
Lohse     Minn
Young     Tex
Moyer     Sea
Mussina   NYY
Wells     Bos
Robertson Det
Westbrook Cle
Bush      Tor
Arroyo    Bos

Cabrera   Bal
Johnson   Det
Clement   Bos
Bonderman Det
Elarton   Cle
Santana   LAA
Maroth    Det
Pavano    NYY
Carrasco  KC
Lopez     Bal
Fossum    TB
Miller    Bos
Meche     Sea
Franklin  Sea

Hernandez CHW
Leither   NYY
Hernandez KC
Rodriquez Tex
Lilly     Tor
Douglass  Det
Waechter  TB
Pinero    Sea
Mays      Minn
Park      Tex
Sele      Sea
Schilling Bos
Greinke   KC
Hendrickson TB  5.90

Oakland ends up with the 4th best rotation.

In order:

Minn- three #1 (Santana, Baker, Silva), zero #2, two #3 (Radke, Lohse), zero #4, one #5 (Mays, but he is a FA now) How did this team miss the playoffs!?

LAA- three #1 (Washburn, Lackey, Colon), one #2 (Byrd), zero #3, one #4 (Santana), zero #5

CHW- two #1 (Buehrle, Garland), two #2 (Contreras, Garcia), one #3 (McCarthy), zero #4, one #5 (Hernandez)

Oak- one Ace (Harden), three #2 starters (Blanton, Haren and Zito) and one #3 (Saarloos)

Cle- One #1 (Millwood), one #2 (Lee), two #3 (Sabathia, Westbrook), one #4 (Elarton) zero #5

Tor- one #1 (Halladay), two #2 (Towers, Chacin), one #3 (Bush), zero #4, one #5 (Lilly)

NYY- One #1 (Chacon), two #2 (Johnson and Wang), one #3 (Mussina), one #4 (Pavano), one #5 (Leiter, now with FL, thats six starting pitchers under contract through 2006 when you include Wright.)

Bos- Zero Aces, Zero #2, three #3 (Wakefield, Wells, Arroyo) one #4 (Clement), one #5 (Schilling)

Sea- One #1 Hernandez, zero #2, one #3 (Moyer, but he is a FA now), two #4 (Meche, Franklin), two #5 (Pinero, Sele) Plus they have Foppert

Tex- one #1 (Rodgers), zero #2, one #3 (Young), zero #4, two #5 (Rodriquez, Park)

Det- zero #1, zero #2, one #3 (Robertson), three #4 (Johnson, Bonderman, Maroth), one #5 (Douglass)

TB- zero #1, one #2 (Kazmir), zero #3, one #4 (Fossum), two #5 (Waechter, Hendrickson)

Bal- zero #1, two #2 (Chen, Bedard), zero #3, two #4 (Cabrera, Lopez), plus Ponson 7.11 ERA

KC- zero #1, zero #2, zero #3, one #4 (Carrasco), two #5 (Hernandez, Greinke) Plus lots of AAA players.  

So?  Can we afford to trade the 25th best pitcher (per ERA) in the AL.  If so, what is the 25th best pitcher worth?  A bat and two prospects?

If not, can we afford to resign him?  What is a 27 year old, former Cy Young winning, left handed SP worth?  Three years/$30 million?  Five years/$63 million?