Final hand, all of your opponents have 17. The dealer has a five showing. You have a hard 12. You can win the table by either winning a double down or swinging your opponents. What's the best play, double or hit?
I'm glad to say my intuitive answer was on target. My initial reaction was: Double, and it's not even that close a call. It's easy to figure out the chances of winning by doubling with a spreadsheet, since the player can only draw one card, and the percentage chance of the dealer ending with various totals from an upcard 5 are readily available. (See http://www.blackjackinfo.com/bjtourn-dealercharts.php ) A player who doubles 12 v 5 will win 38.2% of the time (6 decks, S17). Figuring your chances by hitting and playing for a swing is much more difficult, but I have some software on hand that's useful for that purpose. If you choose to hit in this situation instead, you've got a tough set of circumstances. We'll assume that a push does you no good, and also that winning while your opponents' 17s push is also no good. That means you must hit your 12 until you have a total of at least 19. That gives the dealer at least one number to land on between your total and the 17s around the table. Using that strategy, you'll end up with 19, 20, and 21 approximately 12% of the time each, and you'll bust the other 64% of the time. However, even if you don't bust, the dealer must also end up exactly in between. Once you take that into account, this strategy has only an 8.6% chance of succeeding. Doubling: 38.2% success Hit to 19+, and hope the dealer gets in between: 8.6% If anyone is interested in the method of these calculations, I can try to explain further. I see already that it would be nice to have charts that show various percentages like this.