Actually it'll be more than a year he'll likely be gone. If he gets 18 months, that term won't start till at the earliest, january, that takes him out all of this season, and all of next season. Then, once he's out a jail, he'll still have to serve any suspension the NFL puts on him, which will also probably be year given that his crimes are felonies. So thats 3 years he'll be missing. If he's even allowed back. Last guy to lie to the face of a sports commisioner was Pete Rose, look how that's turned out.
Thats if the jail sentence is only 18 months. With everything I'm hearing about the judge, how he's one of the toughest in the country, and is shocked and appaled by what Vick did, I can't think he'll be going easy on him, especially if he admits to everything he's charged with. Plus he lied to the judge too. 36 months is entirely possible IMO
Thats why I think if the United Football League actually happens, he'll more than likely end up there, as they will surely do anything to grab headlines.