I'd like to come up with some kind of list for the best and worst bullpens. The purpose of this list is to be able to see which teams starters will likely have more or less value than perceived due to their great or terrible bullpen. For instance, Josh Johnson was one of the best pitchers in the game last year but only won 11 starts due to several blown leads by the Marlins bullpen. Not only will a bullpen affect win totals but they can also help or hurt a starters ERA by holding runners left on base by the starter.
Here are some of the bullpens I think will affect their starters numbers the most. (no particular order)
NYY (Joba, Feliciano, Robertson, Soriano, Rivera)
SD (Frieri, Gregorson, Adams, Bell)
SF (Casilla, Affeldt, Romo, Wilson)
OAK (Devine, Wuertz, Ziegler, Breslow, Fuentes, Balfour, Bailey)
LAD (Jansen, Troncoso, Guerrier, Kuo, Broxton)
BOS (Okajima, Wheeler, Jenks, Bard, Papelbon)
CWS (Pena, Santos, Crain, Sale, Thornton)
COL (Morales, Lindstrom, Belisle, Betancourt, Street)
ATL (Sherrill, Moylan, Venters, Kimbrel)
Disagree with anything on my list? Let me know so I can update it.