Although any day at the ballpark is a perfect day in our book, there have been just 23 true perfect games throughout Major League Baseball history. In a perfect game, no opposing batter reaches base. (The difference between a perfect game and a no-hitter? In a no-hitter, although the losing team does not record any hits, at least one batter reaches base-e.g. via a walk.) These 23 pitchers made history. Who do you think will be next?