21+3 Blackjack Strategy: Probabilities and Deck Impact Explained

Ever since Blackjack was invented in the 19th century it has always been popular with casino – and most recently – online casino goers all over the world. 

The simplicity behind Blackjack is that in that time the game of blackjack has barely changed. However, over the last few decades there have been an introduction of side bets – many of which you have probably heard of.

Taking up the option of the double, insurance and Perfect Pairs are three popular side bets. There is one other side bet that can be placed which is a 21 + 3 side bet and it could be argued that it is the one side bet that people know the least about.

Here we will explain the different permutations of the 21 + 3 and reveal why it could potentially be something to consider the next time you find yourself at the Blackjack tables. 

21 + 3 explained 

For many the name of 21 + 3 is a tricky one to understand. Of course the ultimate aim of Blackjack is to try and get 21 or as close to it as possible. Anything over 21 will see the player or dealer go bust, but with a name like 21 + 3 it’s easy to think that a busted score of 24 might be enough to win a hand.

That isn’t the case at all.

The three in the title of the bet doesn’t reflect how many you can be over 21 by, instead it refers to the three cards needed to complete a three card poker hand.

Three card poker? I hear you say. Yes, that’s absolutely correct, 21 + 3 combines two casino favourites Blackjack and 3 card poker into one hand. Let’s break that down in more detail.

Three card poker in Blackjack 

The bet is settled before the calling begins 

When you sit down at the Blackjack table – whether this be at a real or online table, you will see in front of you the option to place your bet in the main betting circle. Flanking that circle to the left is where you can place Perfect Pair bets. To the right is where you can place your 21 + 3 bet. 

The first thing you need to be aware of when looking to place your 21 + 3 bet is that it is a bet that takes place before the main Blackjack hand begins. 

What we mean by this is that by the time each player has been dealt their two hole cards and the dealer has dealt themselves one card, you will know if you have a winning hand or not. 

Once you have either won or lost the 21 + 3 side bet, the main Blackjack hand will then begin.

Three card poker – the different hands and combinations 

Although combining three card poker into a Blackjack hand does potentially sound confusing, the reality is anything but.

The three card poker hand consists of the two cards that the player is dealt alongside the one card that the dealer is dealt. The aim is to then use the value or suit to try and make the best poker hand possible. As traditional Texas Hold’em uses five cards, it isn’t possible to make every kind of poker hand. Instead, these are the following hands that you can make and the odds you can achieve if one of these hands is hit. 

• Suited Three of a Kind: three cards of the same rank and suit.
• Straight flush: three sequential cards of the same suit.
• Three of a Kind: three cards of the same rank and any suits.
• Straight: three sequential cards, e.g., 9-8-7, of any suits.
• Flush: three cards of the same suit in any order.

The odds are as follows.

• Flush: 5/1
• Straight: 10/1
• Three of a Kind: 30/1
• Straight Flush: 40/1
• Suited Three of a Kind: 100/1

What happens after the 21 + 3 bet has been settled?

After a 21 + 3 bet has been settled, the Blackjack hand will then begin. There won’t be any new cards that are dealt. The hand will begin with the two initial cards that the player would have received and the player will play against the card that the dealer would have received. Once the blackjack element of the game begins, players will be able to hit, or stick depending on what cards they have.

Multiple decks can help but the house has the edge

The important thing to remember with a game of blackjack is that there are multiple decks usually in play at any one time. Usually there are at least four decks of cards present in the game, but some games will have at least eight. Depending on how many players are at your table, the number of decks that are present can keep the odds for a 21 + 3 bet a possibility.

However it is worth noting that on average the house holds an edge of just over 13% when it comes to a 21 + 3 side bet. This means that every time you place a 21 + 3 side bet the house does hold a fairly significant advantage. Although the house edge could be off putting for some, others see the potential payouts as a decent shout which is why they see a 21 + 3 bet as a worthwhile option to play.

If a 21 + 3 bet is placed, does that mean a player can’t place any other side bets?

As we have outlined above, a 21 + 3 side bet is just one of the side bets that can be played when playing blackjack. There are plenty of others that can be played at the same time.

A common strategy for some experienced blackjack players is to place a main blackjack bet and couple this with both a 21 + 3 and Perfect Pairs side bet. With Blackjack paying at 1:1 odds, some players want to chase the odds and boost any potential payouts by landing one of the side bets.

Whilst this is a strategy that has been employed by many, it is important to remember that side bets can be expensive to play and can diminish a player’s bank roll quickly.

A 21 + 3 bet is settled before the main blackjack hand begins, players who play 21 +3 are still allowed to make side bets once the blackjack part of the hand plays out. Therefore if the player wants to double, or take up the dealer’s offer of insurance, these are all things that can be done.

As we have pointed out, the one golden rule of any side bet in blackjack is to keep an eye on cost. All of the different side bets can really add up. If players are playing on a tight budget, they just need to be conscious of how side bets could diminish their bank roll.

Conclusion on 21 + 3 blackjack side bet

Whether or not a player sees placing a 21 + 3 as worthwhile really comes down to player preference. There are some who see the different side bets as fundamental to blackjack, whereas there are others who see it as a distraction and an expensive way to play.

Should a player look to place a 21 + 3 and see what it’s all about, the best way to get started is by finding a table with small limits and starting small. We would also advise you just place the one starting side bet as this will help keep your limits under control.

Starting off small will allow a player to see how it works whilst keeping it fun.

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