The head pattern reversal strategy identifies possible price reversal points. Histogram bar pointing up suggests a bullish reversal point while, on the other hand, bar pointing down suggests a bearish reversal point.
Reversal points might appear in both up-and-down trends. So, it's highly recommended to use a filter, such as RSI, William's Percent Range or CCI.
In the screenshots you can how the HEAD FAKE INDICATOR hints good reversal points when working in conjunction with other indicators.