There is a catch though. In random combat Batman wouldn't always win. Batman usually has to be beaten first or needs time to plan before a fight. You might best Batman initially but he is going to run yo ass the next time you meet up. Like if Spiderman ran into Batman and Batman had no prior knowledge or experience with fighting Spiderman, Spiderman most likely wins. He just webs Batman up and swings away. 24 hours later Batman runs into Spiderman again. Batman beats the little **** half to death after careful planning and analyzing Spiderman's weakness. TWIST! Batman let Spiderman easily defeat him the first time to not risk unnecessary injury and gain experience. Batman still wins. He wins when he loses. He always wins, in the end.
