Worf is billed as a proud warrior from a mighty warrior race who live for combat and fighting. His toughness and fighting skills are constantly referred to with awe and reverence. However, he's constantly bested, beaten and defeated; often quite easily by whoever he engages. Whether it's Jem'Hadar, Guinan, Borg, Lore, some guest alien or even other Klingons, he 'gets handled'.
Outside of Holodeck opponents, he seems to lose almost every confrontation he is in. Though he's always talking about battle and his strengths as a warrior, he gets his butt handed to him whenever he actually fights.