Oh, oops. I was typing that off the top of my head, not actually checking.
You lost me here, so let me explain this again. Let's say you've got a human (Medium) and a halfling (Small) fighting an ogre (Large). Instead of applying a -1 size bonus to the ogre's AC and attacks, you apply a +1 bonus to the human's attack roll and a +2 to the halfling's. For grapple checks, the human suffers a -1, and the halfling -2 (though technically, the halfling would probably get a bonus to Acrobatics* checks to escape, but that's a bit too complicated). So when you list the ogre's statblock, his "BAB/Grapple" entry would read "+3/+8" (BAB + Strength only) instead of "+3/+12".
*Acrobatics is the new skill comprising Balance, Escape Artist, and Tumble.
