Blackjack side bets explained

A blackjack side bet is a separate wager, placed before the deal, on something other than beating the dealer: a pair in your first two cards, a poker hand with the dealer’s upcard, the dealer busting. Under six-deck S17 rules the main game costs a basic-strategy player about 0.4% per hand; the side bets below cost between about 1% and 25%, and most sit in the 3% to 8% band. The house edges here are Michael Shackleford’s figures from the Wizard of Odds pages for each bet, which also list other pay tables.

Why side-bet edges are high

A side bet pays fixed odds on an event with a known probability, and the gap between the two is the house edge. A perfect pair at eight decks is a simple case: your first card can be anything, and 7 of the remaining 415 cards match it exactly, so the probability is 7 ÷ 415 ≈ 1.69%, or about one hand in 59. The true odds against are roughly 58 to 1; the bet pays 25 to 1. Even after adding the smaller pays for coloured and mixed pairs, Wizard of Odds’ total comes to 4.10% house edge. Jackpot-sized top prizes are what sell the bet and what hide the gap, because the top prize is too rare to judge from experience.

The main game has a low edge because the player’s decisions reduce it; side bets resolve on the first two or three cards with no decision, so basic strategy cannot help.

House edges at a glance

Figures are for six decks unless stated and taken from the Wizard of Odds page for each bet; pay tables vary by casino, so check the felt. “To one” pays return the stake as well.

The Lucky Ladies figure is the standard pay table; Wizard of Odds reports that the page’s generous table E is far cheaper, which illustrates how much pay tables matter. For Bust Bonus the edge depends on the upcard because the bet is placed after seeing it; the dealer 8 is the cheapest at four or more decks and the dealer 9 and ace are the most expensive. Wikipedia’s blackjack article lists these and others, Bust It among them, and notes that side-bet edges are generally higher than the main game’s.

The bets in more detail

21+3 combines your two cards with the dealer’s upcard into a three-card poker hand. The original version paid 9 to 1 on any flush, straight, three of a kind or straight flush; most modern versions pay a ladder topped by suited three of a kind at 100 to 1. Wizard of Odds lists ten versions with six-deck edges from 3.24% to over 13%.

Perfect Pairs pays on your first two cards: a perfect pair is identical in rank and suit, a coloured pair matches rank and colour, a mixed pair matches rank only. Fewer decks make pairs rarer, so the two-deck edge on the same pay table is 22.33%.

Lucky Ladies pays on a two-card 20, with escalating pays for suited 20s, matched 20s, a pair of queens of hearts, and the top prize when that pair meets a dealer blackjack. The top pay of 1,000 to 1 is the lure; the 24.71% edge is the price.

Royal Match pays 2.5 to 1 on any suited first two cards and 25 to 1 on a suited king and queen. Six versions exist; Wizard of Odds notes that one single-deck pay table paying 3 to 1 on an easy match would favour the player at four or more decks.

Bust Bonus and Buster Blackjack both pay when the dealer busts. Bust Bonus is placed after the upcard is seen and pays by upcard; Buster Blackjack pays by how many cards the dealer needed to bust, up to 250 to 1 for eight or more. Wizard of Odds’ page on the simpler Bust bet, which pays 5 to 2 on any dealer bust, shows a small player edge when the dealer hits soft 17 with six or fewer decks (0.016% at six decks) and a house edge of 1.33% when the dealer stands on soft 17; the dealer bust rate in that analysis is 28.2% to 28.6%.

Lucky Lucky uses your two cards plus the upcard and pays on totals of 19, 20 and 21, with bonuses for 6-7-8 and 7-7-7. The common pay table is among the cheapest side bets at 2.66%, though others on the same page cost up to 12.6%.

Insurance as a side bet

Insurance is offered when the dealer shows an ace. It is a wager of up to half the main bet that the hole card is a ten, paid 2 to 1, and is settled independently of your hand. At a six-deck table, ignoring your own two cards, 96 of the 311 unseen cards are tens:

2 × (96 ÷ 311) − (215 ÷ 311) = (192 − 215) ÷ 311 = −23 ÷ 311 ≈ −7.40%.

The same arithmetic gives −3 ÷ 51 ≈ −5.88% for a single deck and −31 ÷ 415 ≈ −7.47% for eight decks. Taking “even money” on your own blackjack is the identical bet in different clothing; see insurance and even-money maths.

When a side bet is ever worth it

Three narrow cases exist, and all of them depend on information most players do not have.

1. A counter and insurance. The insurance edge above assumes a neutral shoe. When the remaining cards hold more than one ten in three, insurance becomes positive; Hi-Lo players use a true count of about +3 as the threshold, as covered in the Illustrious 18. Wikipedia notes that insurance and Lucky Ladies are the side bets whose outcomes correlate well with the Hi-Lo count, because both pay on ten-rich remainders.
2. A generous pay table. Wizard of Odds’ pages show the same bet ranging from a player edge to a 20% house edge depending on the pays. Royal Match’s single-deck table at eight decks and the plain Bust bet under H17 are documented examples; they are rare and tend to be corrected once noticed.
3. A progressive jackpot that has grown past break-even. Wizard of Odds gives break-even meter sizes for the progressive versions of 21+3, Lucky Ladies and Royal Match. Below the break-even figure the bet is still a loser.

Outside those cases, Shackleford’s ninth commandment applies: thou shalt not make side bets. A £5 main bet costs about 2p in expectation; adding a £1 side bet at 6% raises the round’s expected cost to about 8p.

Related reading

• Insurance
• Insurance and even-money maths
• How the house edge is calculated
• Illustrious 18 index plays