We used to span a string/piece of rope and hang a sheet of paper from it, effectively dividing the screen in half. Did that when we still played the N64 for MarioKart and GoldenEye.
My brother linked me a couple of movies on YTube showing console gameplay from COD: you notice the people aim rougly at a target, and than strafe to hit. :rotfl:
I remember on the N64 playing GoldenEye, we could circle each other, emptying all the ammo for a weapon, and still not kill each other.
You can get a pretty satisfactory experience if you fine-tune the sensitivities and spend some time getting used to it, but imho a mouse just beats it hands down.
* I actually bought a second hand Xbox (first gen). Played for 2 weeks and then put it at a friend's whose Xbox had broken. I guess it's still there.