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Blackjack side bet calculator: 21+3 and Perfect Pairs
Pick the side bet, the number of decks and the pay table printed at your table – or type your own payouts. Every probability is an exact fraction.
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Return to player 96.76%: on average the bet keeps 3.24% of every amount staked on it.
| Outcome | Pays | Probability | About 1 in |
|---|---|---|---|
| Suited three of a kind | 9 to 1 | 0.0207%2/9641 | 4,821 |
| Straight flush | 9 to 1 | 0.207%1296/626665 | 484 |
| Three of a kind | 9 to 1 | 0.504%243/48205 | 198 |
| Straight | 9 to 1 | 3.102%3888/125333 | 32 |
| Flush | 9 to 1 | 5.842%36612/626665 | 17 |
| No poker hand | loses | 90.32%566028/626665 | 1 |
Off the top of a full shoe. 21+3: your two cards and the dealer's up card; A-2-3 and Q-K-A are straights, K-A-2 is not; each hand is paid once, at its highest category. Perfect Pairs: your first two cards. The stake and number of bets are only an example, not a suggestion.
How 21+3 and Perfect Pairs are scored
21+3 treats your first two cards and the dealer's up card as a three-card poker hand. A flush is three cards of one suit, a straight is three ranks in a row, three of a kind is three cards of one rank; a straight flush and suited three of a kind (three identical cards, possible only with more than one deck) pay the most. Perfect Pairs looks only at your first two cards: a perfect pair is the same rank and suit, a colored pair the same rank and color but a different suit, a mixed pair the same rank in a red and a black suit.
With 6 decks a flush comes about once every 17 hands, a straight once every 32 and a suited three of a kind once every 4,821. A perfect pair comes once every 62 hands.
Common pay tables compared
House edge of the 21+3 pay tables in our data:
| Pay table | 6 decks | 8 decks |
|---|---|---|
| Classic 9 to 1 (9 / 9 / 9 / 9 / 9) | 3.24% | 2.74% |
| Five-tier (100 / 40 / 30 / 10 / 5) | 4.62% | 3.70% |
| Four-tier (30 / 40 / 30 / 10 / 5) | 6.07% | 5.42% |
And of Perfect Pairs:
| Pay table | 6 decks | 8 decks |
|---|---|---|
| 25/12/6 (25 / 12 / 6) | 6.11% | 4.10% |
| 30/10/5 (30 / 10 / 5) | 5.79% | 3.37% |
For comparison, the main game played by basic strategy has a house edge of 0.62% (6 decks, dealer hits soft 17, blackjack pays 3:2). Every side bet above keeps several times more of each amount staked.
Why the number of decks matters
More decks mean more identical cards in the shoe, so pairs and suited three of a kind come more often. That is why the same Perfect Pairs table (25/12/6) has a house edge of 6.11% with 6 decks but 4.10% with 8. Check both the payouts and the number of decks before you compare two tables.
What the side bets are and how they are offered online: blackjack side bets.
How it is worked out
Every ordered deal of two or three cards from the shoe is counted exactly, card by card, so each probability is a fraction with no rounding until it is printed. The ready-made pay tables were also checked with our own independent simulation of 20,000,000 hands per bet for 6 and 8 decks; every result agreed within its margin of error.
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