We love to see how much money we can make vs. the amount of buying power used. so if OO could give us rate of return or return on investment vs. buying power used, then we could use that to compare strategies to see how to optimize our profit with the buying power we are willing to use. For example if #1 strat paid .40 per $1 of BP and #2 strat paid .65 per $1 of BP used, we might prefer that (depending on other considerations)