The chances of getting winning combinations. 40,000:1 is a chance of getting a Royal Flush. 10,000:1 is a chance of getting a Straight Flush. 423:1 is a chance of getting a Four of a Kind. Only one of 86 combinations can be a Full House. The chance of getting Flush is 93:1. Only one of 85 combinations can be a Straight. Only one of 13 combinations can be a Three of a Kind. 8:1 is a chance of getting a Two Pairs. Only one of 5 combinations can be a High Pair. Computer Straight Poker Full House.