I was watching SportsCenter and they were talking about Padres closer Trevor Hoffman, who recently converted his 500th save. The promo for the segment ended with "Is he a Hall of Famer?". You have got to be kidding.
He is the only person in history to reach 500 saves, and he is unlike most closers in that his best pitch is his changeup, not his fastball. Most agree that Mariano Rivera is a Hall of Famer, and he has 419 saves right now, and is two years younger than Hoffman. Let's say Hoffman retires with about 550 saves, and Rivera has 445 (42 this season) at the end of this season. He will still have to average 40 saves for over 2.5 years to pass Hoffman. That seems unlikely considering his cutter will get slower and slower as he ages (Compared to a changeup, to which a speed difference will mean less), it will probably take longer than that.
It seems as if the only thing keeping Hoffman from the Hall of Fame is a lack of Postseason success. Rivera is probably the greatest postseason closer ever, but Hoffman isn't that bad. 2.70 ERA in the Division Series and a 2.08 ERA in the NLCS. The only thing wrong is a 9.00 World Series ERA, but that was only 2 innings of pitching. Are 2 innings of pitching really going to keep one of the best changeups ever from the Hall of Fame?