Double Bonus

Double Bonus raises the stakes on four-of-a-kind: Four Aces pay 160-for-1, Four 2s–4s pay 80-for-1, and Four 5s–Kings pay 50-for-1.

The full-pay 9/7/5 schedule balances those quad awards with a 9-for-1 Full House, 7-for-1 Flush, and 5-for-1 Straight. With perfect play it returns 99.11%, but its optimal holds differ meaningfully from Bonus Poker.