25-50-100-20…where, at the end of the series when you (hopefully) win you gain one (1) unit of profit for the entire series. ~The plain Martingale is a double-on-each-loss progression, ie.
Well if you are going to Martingale the field-bet you might as well Grand Martingale the Field, to make one-unit per wager instead of one-unit per series.