Surprise Maneuver

If you have sneak attack, when you attempt a combat maneuver check against a creature that you are flanking or that is denied its Dexterity bonus to AC against your attack, you gain a bonus on the combat maneuver check that's equal to %1. If you have the studied combat class feature, you can use studied strike on a combat maneuver check. When you do so, you gain a bonus on the combat maneuver check equal to %2.