Mark McGwire

McGwire is one of the highest-peak power hitters to ever play first base. His career slugging and OPS+ aren’t just good; they’re historically loud for a player with his era and injury interruptions. He didn’t need 650 plate appearances to crush 45–50 homers, which speaks to the rate of damage. The walk totals matter too, because pitchers were terrified to challenge him, and that kept his OBP high. His best seasons are game-breaking: a handful of plate appearances could equal a team’s entire scoring output. Injuries and missed time limit his counting stats, but the offensive impact per at-bat is elite. He also produced elite isolated power that few players in history can match. In terms of pure “how fast can you generate runs with one bat,” he’s near the top. If you value peak dominance heavily, McGwire earns a spot solidly in this tier.