Odd is better then even.

When playing agonist a Hordes player, you want to roll Odd numbers when you roll for hit location. This gives you the best shot a crippling an aspect of the Warbeast. Even hit locations mean you have to crew though about 60% of that anspect with out being able to cripple it (unless it's almost dead and you roll all the way around to finish the beast). It's not that big a deal, but if you have models with the sniper ability almost always call the odd numbered spirals.