Likely dumb vig question

[Daliman]

Let's say I'm making a bet with a friend, and we obv split the vig. If the game is -110 both sides, pretty obv an even $$$ bet, but if it is a higher number like say -300/=240, is it as simple as going to the middle? It's seems I have heard something somwhere where going to the middle actually infers a slight edge to one side, ( I think the negative?) as the higher negative must be offset by a higher spread or some crap. EIther way, was just wondering, flame if needed.