His childish personality occasionally hampers his effectiveness. When Brook fights, his battles often have a comical element to them, including making a few of the members of his own crew fall asleep while fighting the Flying Fish Riders, playing dead halfway through a battle, or launching himself at an enemy with erroneous results. Brook is a talented swordsman, has extraordinary speed due to his light frame, and is astonishingly difficult to harm because of his undead state. Roger was still active, Brook, in all respects, is a veteran pirate (though these attributes are somewhat downplayed by his overall demeanor, along with the fact that his isolation in the Florian Triangle seemed to have eroded his knowledge of modern society).
Due to his previous experiences and skills that he amassed from the days when the Pirate King Gol D.
As much as Brook normally goofs around on the ship engaging in acts of silliness with Luffy, he is still a formidable opponent.