First of all..let's assume Bat's has a giant book of prep, that is the ONLY way he beats anyone that overpowers him anyway. Let's also assume Bat's Batcomputer has a comicvine account (that's the only way to account for his edge in battle), so that allows him the foreknowledge for just about everyone's abilities.
How many pages are in his prep book (at least 50 pages likely)? He continually adds to it as he trusts no one, so it must be a lot. For everyone he befriends he likely spends time writing notes on how to beat them down (probably even has prep for Alfred).
So the ultimate question is not who Bats can beat, but rather..who is the highest level character Bats could beat with his prep book. At what point does Bats say.."I'm sitting this one out, or I rather retire than fight that guy."