This is hugely historic. Stark mentioned briefly that the next one to win 300 may not have been born yet. The only other oactive pitchers with even 200 wins are Andy Pettite and John Smoltz and they only have 220 and 210 respectively. It’s going to be a very very long time before another human being wins their 300th Major League game.
Jayson Stark: Randy Johnson's 300th victory is one to remember – ESPN