Inaccurate?

Rabid Wolf Strike

(Tome of Battle: The Book of Nine Swords, p. 88)

Tiger Claw (Strike)
Level: Swordsage 2, Warblade 2,
Components:
Casting Time: 1 standard action
Range: Melee attack
Target: One creature

You foam at the mouth and scream in rage as you make a powerful attack against your enemy. You set aside all thoughts of defense as you lunge forward.

For a split-second, you unleash the barely controlled, primal rage that surges within you. As part of this maneuver, you make a single melee attack. You gain a +4 bonus on this attack roll and deal an extra 2d6 points of damage. You take a ?4 penalty to AC until the start of your next turn, as this wild strike sends you off balance and hinders your defenses.