42 is the Answer.

Here is a list of every Red Sox pitcher who compiled 20 or more saves from 1997 through 2013.
- Jonathan Papelbon (219)
- Derek Lowe (85)
- Tom Gordon (68)
- Ugueth Urbina (49)
- Heathcliff Slocumb (48)
- Keith Foulke (47)
- Mike Timlin (27)
- Alfredo Aceves (27)
- Tim Wakefield (22)
- Koji Uehara (21)

Note that this list excludes several would-be closers who failed to get to 20 saves:
- Joel Hanrahan (4)
- Andrew Bailey (14)
- Mark Melancon (1)
- Daniel Bard (5)
- Curt Schilling (9)
- Rod Beck (6)
- Butch Henry (6)
- John "Way Back" Wasdin (3)
- Rich "El Guapo" Garces (5)

Here is the same list for the Yankees:
- Mariano Rivera (652)
- Rafael Soriano (44, but only because Rivera tore his ACL last year).

Happy trails, you magnificent bastard.

Seriously, spend some time on Rivera's Baseball Reference page. Look on his works, ye mighty, and despair.

Media Rights and Market Size

Last week, Larry Granillo found an old article in Sponsor magazine ("the national weekly of TV and radio advertising") that listed the TV and radio deals each MLB team had in place for the upcoming 1961 season. The chart is here, and is pretty cool on its own. Larry did a good job breaking down who spent what where, but I was personally more interested in the "why". Several companies (like American Tobacco) sponsored teams in multiple markets; how did their advertising agency decide to pay $140,000 for a third of the Red Sox' rights, but $200,000 for a third of the Tigers' rights?