It'd be a two minute fight, so long as Superman took the kid-gloves off.
Even with the kid-gloves Superman's got a strong edge by being, you know, invincible.
You've CLEARLY never read The Dark Knight Returns, or whichever Frank Miller book it was in which they fought.
Being invincible doesn't change that fact that it would be supergenius vs farmboy.
Probelm is, the fight is always going to be biased towards whomever the writer is the big fan of. "The Dark Knight Returns" is obviously, judging from the title, biased towards Batman so obviously he's going to do better.
I could write a book called, "The Man of Steel Returns!" and have Superman use Batman as pogo-stick.
In "reality" Superman vastly out-powers Batman. Superman is an invincible, super-strong, super-smart, alien from another planet who has a *single* weakness in the very rare kryptonite. Unless Batman gets ahold of some (granted not out of his abilities) he doesn't have a chance. No tool or weapon he has is going to penetrate Superman's skin or move faster than him and no punch he throws Superman is going to feel as anything more than a tap on the shoulder. There's *nothing* Batman can do to bring down Superman, again, short of getting ahold of Superman's one weakness and some may argue that'd be fighting dirty, which Batman wouldn't do.
It wouldn't be a fair fight. All Superman has to do is super-speed up to Batman and break his arms, or eye-vision a streetpoll on to Batman, or use his super-breath to either blow Bats away or freeze him. Superman is just too much. Hell, if he sees Batman coming at him with Green-K all Superman has to do is fly or run away at near the speed of light -at his fastest.
Nah. A "true" Batman vs. Superman can never be done "right" and it wouldn't make sense anyway. I'd much rather see them teaming up to ight a common foe it's truer to the comics and much closer to their respective natures.