C'mon people. I love Spider-Man to death and I think this fight is 50/50, but don't give him too much credit. He's a street-level hero for a reason.
Actually, Spiderman had been upgraded to one of "Earth's Mightiest Heroes" last time I checked. New York City has always been the center of the Marvel Universe. The greatest villains ever have rolled through that town time and time again. It's a city that has almost as many heroes as it does citizens. This is the "street" Spiderman takes care of. I'm pretty sure the same can't be said for Gotham.
At least most of his villains have actual powers instead of just being freaks. (Look like a penguin, dress like a clown, twerp in a scarecrow mask, half his face messed up etc...)
Be being a straight-up better hand-to-hand fighter and a better strategist/tactician who also has many, many gadgets at his disposal. Yes, Batman could throw a gas-bomb at Spider-Man; Peter's ability to dodge isn't infallible.
Batman's h2h isn't infallible either. I think Spiderman's strength alone overwhelms it. Besides, it's nothing Spidey hasn't faced before. I know it's tough to swallow; but Bruce Wayne is not the greatest martial artist to ever live...he's not even the best in his own circle of friends.
As for the gas bomb, while i'm fairly confident in Spiderman's ability to web it and toss it away before it explodes and in his ability to avoid gas in an open area, i'm pretty sure Batman never uses it as a first resort. Spiderman's superior and superhuman speed, agility, strength etc...is more than enought to subdue Batman in less than a minute.
All he really has to do is web him up and the fight is over. Spidey's webbing is as strong as steel; and it takes over an hour to dissolve.
As for tactics? I'd make the arguement that "on the fly" Spiderman's tactical sense is just as good as Batman's. Give Batman some prep, and he'll out class Spiderman's tactics/strategy; but Spiderman has thought up some pretty ingenious methods of beating enemies physically superior to himself, on the go, as well.
his spider-sense isn't perfect. He does NOT have precog, he only has a feeling that says, "Hey, be on-guard, there's something coming." Peter can be faked out.
Well, you don't have a great understanding of how his spider sense works at all do you? You really are underrating it. It's an instinctive reaction or body movement to avoid incomming danger (and has many other uses); like when the doctor hits your knee with the little hammer. Spiderman has to concentrate very hard to resist it.
Here is a neat link I got from brainchild's sig http://www.geocities.com/spydr7/
With that said, Spiderman's ability to dodge what Batman throws at him is MUCH greater than Batman's ability to dodge what Spiderman throws at him.
Seriously, what is so hard to accept about the fact that Spiderman is a superhuman in a suit with super powers. (Wall crawling, Super Leap, Super strong webbing, Spider Sense, 15 ton class Strength, Super Agility, Super Durability etc...)
As opposed to Batman who is just a uh...guy in a Batsuit.
I'm sorry, but as far as stats go it's pretty black and white to me. Spiderman obviously outclasses Batman, and if written realistically, Spiderman will take out Batman 9 out of 10 times. (The other one time the luck factor might help Batman)
If written in a comic book, depending on whose book it is, it'll probably be a draw. Just because Batman has enough fan support to prevent himself from losing. That is the same reason Batman took a punch from Superman without humanly possible reasonable explanation other than the fact that "Superman didn't want to kill him."