The 4th game is on ESPNU.

ESPN/ESPN2/FX have a distribution of 100 million

FSN has a distribution of 80-85 million:

http://www.comcastspotlight.com/network/fox-sports-net

http://uabsports.cstv.com/genrel/010511aaa.html

Versus has a distribution of 79 million:

http://sportsillustrated.cnn.com/2011/hockey/nhl/04/19/tv-contract.ap/index.html?eref=sihp

ESPNU is 68.5 million:

http://www.espnmediazone3.com/us/media-kits/espnu/espnu-fact-sheet/