The 2015 MLB Hall of Fame class is historically impressive.

The following four players are all be headed to Cooperstown this summer, per the MLB Twitter account:

  • Craig Biggio
  • Randy Johnson
  • Pedro Martinez
  • John Smoltz

As ESPN Stats & Info points out, this is the first time since 1955 and just the third time overall that four players will enter the Hall in the same year.

That’s an incredible feat, but the big question is where the class ranks all-time. What follows is a look back through baseball history to see just which groups are the best of all.

For the purpose of these rankings, each class consists of the players elected by the Baseball Writers’ Association of America in a given year. That means that players, managers and officials who entered the Hall thanks to the Veterans Committee weren’t part of the equation.

As for the ranking criteria, the most important aspect taken into consideration was the collective WAR of each class. There was also a focus on how many players it took to compile that WAR, as the classes vary in size from five to two.

Plus, the individual accomplishments of particular players—all-time records, career milestones, MVP awards and Triple Crowns—also determined where each class ended up in the rankings.

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