How is Max Drawdown Calculated?

How exactly is Max Drawdown Calculated?

My system stats currently display:

Max Drawdown 10.56% (20060515 to 20060516)

The most a postion has ever gone against me is

by $2790 … 55 pips in USDJPY; about 2.2% of equity.

How do you come up with 10.56% for Max Drawdown?

Just glancing at your chart: your overall system equity went down from 120K to 110K between the 15th and 16th. The exact numbers work out to 10% of equity.