Mariano Rivera, the first player in history unanimously elected* to the Hall of Fame, is as good a player as anybody to be that guy.
So too would have been Ken Griffey Jr., or Randy Johnson, or Joe Morgan, or Carl Hubbell.
What Rivera's unanimous selection tells us is as much about the changing electorate -- purged as it was, a few years ago, of non-working writers; far more transparent, and arguably far more accountable, than voters in the past, thanks to BBWAA changes and Twitter swarms and Ryan Thibodaux's ballot-tracking project -- as it is about Rivera's greatness.