How much you win depends on which three-card hand you get, with each one paying different odds, more of which below. Equipping yourself with advanced winning strategies and doing your reading can tip the scales a little more in the player’s favour. If your first two cards plus the dealer’s up-card combine to provide one of these five hands then you win your 21+3 blackjack bet. These odds are based on a standard round of Blackjack for the casual player. Typically there will be a 21+3 box on the table in which you place your stake for the side bet. You place the bet before your cards are dealt. Suited three of a Kind – Three cards of the same value/face card and the same suit.Straight flush – Three cards of consecutive values that are all in the same suit.Three of a kind – Three cards of the same value/face card.of the Dealer exceeding 21 4.3.Mathematical Advantage of the House 5.Basic Strategy 5.1.Blackjack Chart 1 Deck 5.2.Blackjack Chart Table Several Decks 6.Counting cards 7.Conclusions. Straight – Three cards of consecutive values, such as 2-3-4. All the rules, odds, and strategies to improve your blackjack game strategy Do you think you can win at Blackjack.In the 21+3 blackjack side bet you bet on whether the first two cards of your hand and the dealer’s face-up card combine to make one of the three-card poker hands below: It mixes blackjack and three-card poker to offer some attractive odds. What is 21+3 blackjack? This popular side bet can be placed alongside your initial bet in the casino classic.