Rob's asking the right question. 2011
@Alistairovereem is the most complete heavyweight to ever step in a cage, and it's not especially close.
Look at what he held at the same time:
🏆 Strikeforce heavyweight champion
🏆 DREAM heavyweight champion
🏆 K-1 World Grand Prix champion
That last one is the separator. He won the 2010 K-1 GP by going through Tyrone Spong, Gökhan Saki and Peter Aerts in a single night. That's the most elite kickboxing tournament on the planet, won by an MMA fighter. No other MMA heavyweight has done it.
Then his UFC debut: Brock Lesnar, former UFC champ, the biggest draw in the sport. Overeem stuffed the takedowns, walked him down against the fence, and ended it in round one with a body kick to the liver.
Elite striking. Dangerous submissions (the guillotine was lethal). A clinch nobody could survive. Size and power at the top of the division.
Fedor had the aura. Cain had the cardio. Stipe had the longevity. But for a peak snapshot, nobody combined striking, grappling and finishing power like Übereem.