Over/Under 13 (Blackjack Side Bet)

Our guide to the Over/Under 13 Blackjack side bet including the rules, likelihoods and odds, payouts, house edge, strategies, and FAQ.

Side bets in blackjack add excitement to a round of the game and give the players an opportunity to win an extra amount. The Over/Under 13 side bet is considered to be quite a profitable one and this article covers everything about one of the most popular side bets.

What Is Over/Under 13

The Over/Under 13 is actually a pair of side bets on whether the player’s first two cards dealt will be a total of either under 13 or over 13. So, the bet is on the sum of the two cards dealt to the player.

Rules

The Over/Under 13 side bet has simple and straightforward rules:

  • It is an additional bet that is available only on those blackjack tables that have the appropriate layout
  • The bet is placed on the assumption that the total of the first two cards of the players will either be over 13 or under 13
  • The bet is placed right before any further cards are drawn
  • Aces count as one point
  • The bet amount can be the table minimum or higher but should not exceed the original bet amount
  • Even money is paid for winning the over or under 13 side bet. The bet loses if the total of the player’s cards equal 13 or if it is just the opposite of the Over or Under 13 side bet placed
  • In some casinos, a bet on a total of exactly 13 is allowed and it pays 10:1
  • In some games, if the dealer shows an ace, insurance is offered after the Over/Under 13 bets are settled and cleared
Over/Under 13 Rules (Blackjack Side Bet)
Over/Under 13 Rules (Blackjack Side Bet)

How the Over/Under Side Bet Works

In a standard game of blackjack, bets are placed in the normal betting spot at the beginning of the game. Each individual player is dealt two cards. It is then time for the players to place the optional over/under 13 side bets in the small circles to the left and right of the central betting spot. These side bet circles are labeled ‘over’ and ‘under’.

As with most types of side bets, the over/under side bets are placed before the deal. These are optional side bets and placed only at the discretion of the player. The bet placed in the over circle implies that the total of the first two cards will be more than 13. Similarly, the player placing a bet in the under circle is betting that the sum total of these cards will be less than 13. These are all even money bets.

Aces count as one, the King, Queen, and Jack cards count as 10 while all the other denominations count as their face value when the total is determined for the over/under 13 bet.

Analyses of Over/Under 13

The Over/Under 13 side bets are actually two separate side bets with different probabilities and house edge. Alongside, there is another Exactly 13 side bet that some casinos allow to be placed by the players.

Under 13 Side Bet

In the under 13 side bet, the player bets that his first two cards will have a sum total that is below 13. The betting amount can be anything but not higher than the original betting amount. The payout is 1:1 if the player wins. The below table shows the probabilities and house edge of Under 13 side bet with the different number of decks of cards.

DecksProbabilityHouse Edge
144.95%10.11%
244.96%10.08%
444.97%10.07%
644.97%10.07%
844.97%10.06%

Over 13 Side Bet

The Over 13 side bet is the exact opposite of the Under 13 side bet. With the basic rules remaining the same, this side bet is placed on the expected outcome of the sum total of the first two cards of the player being over 13. The Over 13 side bet is more popular because it has the lowest house edge and the best odds of winning, especially when played using the card counting strategy. The following table shows the statistics in detail:

DecksProbabilityHouse Edge
146.61%6.79%
246.68%6.65%
446.71%6.58%
646.73%6.55%
846.73%6.54%

Exactly 13 Side Bet

Some casinos allow the Exactly 13 side bet too. In this, the player bets that the sum total of his first two cards will be exactly 13 and not anything under or over it. The probability is definitely lower but the winnings pay 10:1. Here are the details with the different number of decks of cards in blackjack.

DecksProbabilityHouse Edge
18.45%7.09%
28.36%7.99%
48.32%8.44%
68.31%8.58%
88.30%8.66%

Card Counting & Over Under 13

With regards to the Over/Under 13 side bet, the card counting system works well for some, though not in the long run. This is obviously because the house advantage changes throughout the game. As a basic card counting strategy, an excess of high cards in a deck would mean that the probability of a hand totaling over 13 is high and vice versa.

Now, devising an optimal card counting system to determine when the over or under bets would be advantageous will need to be done on the basis of the effect of removing each of the individual cards from the deck. Also, card counting is done in different manners by different players and while some may find it useful, others can hardly gain an edge from it.

The “Over Count System”

The Over Count system is an unbalanced running count system that can be used to gain a competitive advantage while playing the “Over Under 13” side bet in blackjack. The Over Count is a two-level counting system, for instance, aces and deuces count +2 and that is why it is a simpler way to learn and play than the other systems. The unbalanced over count system does not involve any “under” bets, however, the gains on these over bets are so substantial that the player can play the basic strategy through the negative counts and be on the profitable side.

Over/Under 13 FAQ

Here are the common questions about the Over/Under 13 side bet answered in brief:

Is card counting helpful with the Over or Under 13 side bet?

Card Counting is largely helpful with the Over or Under 13 side bet because a count of the high cards and low cards in a deck can determine the outcome of this bet to some extent. However, different players might find card counting to be useful or not so useful depending on their playing strategies.

Is the Over/Under 13 bet worth it in Blackjack?

The Over/Under 13 is a popular side bet and quite worth it in blackjack. The Over 13 has a lower house edge compared to the Under 13 and hence, it is played more often by blackjack players.

What are the odds of winning a Over/Under 13 side bet?

As a blackjack side bet, the odds of winning a over/under 13 are quite good. This is because of a lower house edge of Over 13 and Under 13, which are 6.555% and 10.067% respectively.

What is the payout for Over/Under 13 side bets?

The payout for Over/Under 13 side bet in blackjack is 1:1. However, it may vary slightly depending on the casino. The dealer wins if the player’s hand equals 13.

Is Over/Under 13 profitable in Blackjack?

With good odds of winning, a comparatively lower house edge, and application of card counting techniques, the Over/Under 13 side bet can actually be profitable for blackjack players.

That precisely sums up everything about the Over/Under 13 side bet in blackjack. While it may not bring the players profits always, it is definitely worth playing using the right strategies, at times.