The Deep Crab Pattern The Crab is a Harmonic pattern discovered by Scott Carney in 2001. The critical aspect of this pattern is the tight Potential Reversal Zone created by the 1.618 of the XA leg and an extreme (2.24, 2.618, 3.14, 3.618) projection of the BC leg but employs an 0.886 retracement at the B point unlike the regular version that utilizes a 0.382-0.618 at the mid-point. The pattern requires a very small stop loss and usually volatile price action in the Potential Reversal Zone.