We can dynamically define the risk of an iron fly to save capital compared to a straddle and also take advantage of market skew. To incorporate the market skew, probabilities or delta are used to determine the strikes and define the risk.
Our study on 45DTE SPY has shown that dynamic iron flies receive a much larger potential ROC compared to straddles. However, this comes at the cost of a slightly lower probability of profit. And like straddles, the profit target of dynamic iron flies should be 25% of the received credit.