Three things to note about eligibility:
1. To be eligible for the Hall of Fame, you have to have played ten seasons
2. You have to have been retired
3. Your name can't show up on any extra-curricular lists on Bud Selig's desk
That's it. And as of tonight, Berkman will have played ten seasons, because today is the 10th anniversary of Lance Berkman's major league debut. Is he a Hall of Famer? That's to be debated another time, but congratulations to Lance.