All successful current and past UFC fighters are athletic. Depending on the style, some rely on their exceptional striking speed and endurance to overwhelm opponents like Demetrious Johnson, while others like Brock Lesnar might use sheer strength, explosiveness, and agility to land powerful blows and takedowns. And there are genetically gifted who have it all.
BKFC is a promotion that organizes bare-knuckle boxing events where the rules are similar to boxing using only handstrikes, but without gloves. In contrast, the UFC promotes MMA matches in which fighters can strike with all limbs, wrestle, and fight on the ground.