In a growing number of casinos, the tables are spotted with additional wagering marks, specific places on the felt where players could make side bets. Blackjack side bets are not offered to make the game more fun for the players and give them more ways to make money—they’re offered to make the game more profitable for the casino. The odds are always abominable.
One common side-bet offered in virtually every casino is the option to take “casino insurance” or “even money” when the dealer is showing an ace. Insurance costs a player half the amount of his usual wager, and pays 2:1 (effectively winning back the original wager) if the dealer has a natural. To be fair, a 2:1 bet should have 1 in 3 odds—but there is only a 4 in 13 chance, giving the house a 2.6% advantage.
Even money is an offer to take a 1:1 payoff on your blackjack rather than the usual 3:2. Mostly, it’s the same thing: you’re forfeiting 33.3% of your winnings on a 30.7% chance, giving the house the same 2.6% take in the long run.
The only exception to this assessment by counting cards. This will give you a rough approximation of the actual chances that the dealer’s hole card is a ten—and when those chances increase to 33.3%, both insurance and even money become fair wagers.
This is another common blackjack side bet: wagering, for a 1:1 payoff, that the player’s initial hand will be over or under 13, otherwise called OU13 (aces count as one for this bet). Though the odds of “over” are a little better than the odds for “under,” hands that are exactly thirteen are an automatic loser for the player, which gives the house an 8.28% advantage, no matter which way you bet.
Another common wager is betting, at 7:1 odds, that either the dealer of the player (but not another player) will have a blackjack in the next hand dealt. Odds increase to 15:1 if you wager that the player or dealer (only) will have the blackjack. Since there is only an 4.73% chance a blackjack will show at all, the house advantage approaches 10% for either bet.