The pattern incorporates the 88.6%XA retracement, as the defining element in the Potential Reversal Zone (PRZ).
The B point retracement must be less than a 61.8%, preferably a 50% or 38.2% of the XA leg. The Bat utilizes a minimum 161.8%BC projection.
In addition, the pattern within the is extended and usually requires a 127% calculation. It is an incredibly accurate pattern and requires a smaller stop loss than most patterns.