Bullpen K/BB

While most certainly not a complete picture, the strikeout to walk ratio is a decent measure of pitching effectiveness, especially when considering some of the potential fallacies created by competitive inequality and small sample size. 

Coming into the 2012 season, only five bullpens had been able to amass a K/BB ratio of over 3.00 for a season:

1. 1994 Montreal Expos - 3.41 K/BB
2. 2010 San Diego Padres - 3.32 K/BB
3. 2006 Minnesota Twins - 3.28 K/BB
4. 2003 Los Angeles Dodgers - 3.15 K/BB
5. 2011 Colorado Rockies - 3.04 K/BB

Nearing the quarter pole of the 2012 season, the St. Louis Cardinals are on pace to top that mark with a 3.68 K/BB, but they aren't even in the vicinity of the current MLB leaders.

The Texas Rangers bullpen is currently sporting a 10.29 K/BB ratio. 

To put that into perspective, the single season mark for an individual pitcher is Brett Saberhagen's 11.00 in 1994 (the strike shortened season).  Cliff Lee's 10.28 K/BB ratio is second on the list.