When a player with multiple attacks grapples, do they get the grappler roll at there highest BAB or the BAB of the attach. ie
A monk has 3 attacks +10/+8/+5, if the monk is using there 2nd
attack do they use +8 or +10?
Anytime, it's what the rule boards are for! I've had many-a quick game questions answered quickly, accurately, and with page numbers to boot! (ack! I sound like an info-mercial!!) *whacks self sensless and shuts up*
As for why not the highest BAB? Maybe he decided to grapple after having made the first attack. It's reasonable, if say, you missed your first grapple attack, or that you use a stunning attack before you attempt to grapple your stunned opponent, or that first attack defeated the first opponent and you decided to grapple the second opponent.
My opinion is that an opposed grapple check fits the definition of an 'attack roll', and that modifiers that apply to attack rolls (like the bonus from Bless) should affect the result.
Others prefer to consider a grapple check as distinct from an attack roll, and therefore such modifier do not apply.