Mark McGwire – 65*
McGwire didn’t hit 70 home runs again in his career after an electrifying 1998 season. But he came close in 1999 as he demonstrated frightening consistency. Yes, we’ll mention again that he used PEDs but his accuracy remains impressive. This time he hit over 50 home runs for the fourth consecutive season.
The Cardinals star ensured his place in the history books by smashing 135 homers in two seasons. That’s a ludicrous achievement even if he cheated. It will be fascinating to see if a modern player can use sports science to eclipse these steroid-assisted records or if they’re insurmountable (via Defector).