7 Big Mistakes Blackjack Players Make (and How to Avoid Them)

Blackjack Table

Blackjack is one of the best casino games in terms of your chances of winning, but the catch is that you must use good strategy to boost your profits.

Many players skip learning strategy and head straight for the tables. These same players make serious mistakes that severely reduce their odds of winning.

What are these mistakes? And how can you avoid repeating the same pitfalls that other players deal with?

Find out as I cover the 7 biggest mistakes that blackjack players make and what you should do instead.

1. Trying to Get as Close to 21 as Possible

Most players realize that they have to beat the dealer to win at blackjack, but where some players go wrong is thinking that they must shoot for 21 to accomplish this feat.

While it’s true that getting close to 21 increases your chances of winning, there are many situations where you should stand even when it doesn’t seem ideal.

Here’s an example:

  • You have 12.
  • This leaves you 9 points away from 21.
  • The dealer’s upcard is 5.

Novice blackjack players tend to hit in this situation because they’re so far away from 21. Furthermore, you have 9:4 odds of getting 2 9 or an ace without busting.

But correct strategy suggests that you stand in this instance. The reason why is because dealers must reach a hard 17 or higher before they can stand.

In the example above, the dealer must draw for at least two cards to reach a hard 17. Many card combinations will cause them to bust while pursuing this with a 5 upcard.

Long story short, you’re playing the dealer rather than going for a pretty score, and understanding basic blackjack strategy helps you realize when to stand with a low total.

2. Not Studying a Blackjack Strategy Chart

The point of this post is to discuss the biggest overall mistakes that blackjack players make, but there are also many small gaffes players repeat because they don’t know basic strategy.

Here are a few common blackjack strategy mistakes:

  • Standing on 12 when dealer’s upcard is 2 or 3.
  • Splitting a pair of 10s.
  • Not splitting a pair of 8s.
  • Doubling down on 11 when dealer is showing ace.
  • Hitting on 11 when the dealer’s upcard is 10.
  • Standing on soft 18 when the dealer’s upcard is 9.

It’s understandable why players make these mistakes because nobody naturally knows how to handle every strategy situation. In fact, it took numerous computer calculations to develop optimal blackjack strategy.

The truth is that there’s no excuse for failing to understand basic strategy. All you need to do is look at a blackjack strategy chart to know how to play each situation.

A strategy chart is a color-coded guide that shows when you should hit, stand, split, double down, and late surrender (if available) based on your score and the dealer’s upcard.

You simply look at your score (running along the left side) and the dealer’s upcard (running across top), then scan down to find what action you should take. Here’s an example:

  • You have a pair of 10s.
  • The dealer’s upcard is 6.
  • The strategy chart shows to stand.

Strategy charts are perfect for online blackjack because there’s no pressure to act in a timely manner. You can stare at your chart as long as you want and figure out the optimal play.

But land based casinos are a different matter because the dealer tries to keep the game moving at a reasonable speed. This becomes impossible when you’re staring at a strategy guide every time it’s your turn to make a decision.

I recommend that you study a blackjack strategy chart before heading to a brick and mortar casino.

Of course, you can still refer to your chart from time to time. But don’t make a habit of doing this for every single play.

3. Choosing Blackjack Tables with Poor Rules

One of the most underrated aspects of blackjack strategy has nothing to do with how you play hands. Instead, it involves knowing how blackjack rules affect the house edge so that you can pick the best tables.

The main rule that you want to look at is how much you’re paid for a natural blackjack, where your first two cards equal 21. Ideally, you’ll play at tables with 3:2 blackjack payouts.

You want to avoid tables with 6:5 payouts because this increases the house edge by 1.40%. All you need to do is look at the center of a blackjack table to see whether 3:2 or 6:5 payouts are offered.

It’s also important to know how many decks are used in a blackjack shoe.

Casinos used to offer single deck blackjack, which is the best-case scenario. But many casinos today offer 6-deck or 8-deck games, which raise the house edge by 0.54% and 0.57%, respectively.

Be careful when you see single deck blackjack games offered because they’re often accompanied by 6:5 natural payouts. The single deck doesn’t come close to canceling out how much 6:5 payouts increase the house edge

Other rules to look at include the following:

  • Double down – House edge decreases by 0.25% when you can double down on any total, versus only doubling on 9 through 11.
  • Dealer stands on soft 17 – House decreases by 0.20% when the dealer stands on soft 17, rather than hitting.
  • Double down after splitting (DAS) – House decreases by 0.17% when DAS is available.
  • Re splitting aces (RSA)– House decreases by 0.08% when you can re split
  • Late surrender – House decreases by 0.07% when late surrender is available.

One more point worth noting is that you should avoid novelty blackjack games if your main goal is to win.

Some casinos offer party pit and poolside blackjack games, which have a fun and vibrant atmosphere. However, these tables include the worst rules imaginable because they can still attract casual players.

4.  Taking Insurance & Making Other Side Bets

Many casinos offer you insurance when the dealer’s upcard is an ace (also 10 in some games). You’re paid 2:1 in the event that the dealer has a natural blackjack.

We’ve been conditioned to think that insurance is a good thing based on cars and health insurance. This is why it feels natural to insure yourself against a potential dealer blackjack.

But the reality is that this is just a bad side bet in disguise. Here’s the math to explain why this is the case:

  • 16 cards (four suits of 10 to K) will make the dealer’s blackjack when they’re showing an ace.
  • 36 cards (four suits of 2 to 9) won’t make the dealer’s blackjack.
  • This leaves 9:4 odds of the dealer getting a blackjack.
  • Your payout is 2:1.
  • The dealer won’t have a blackjack enough times to make this bet profitable.
  • The house edge is over 7% on blackjack insurance.

Even table games with poor house edges like American roulette (5.26% house edge) and Caribbean poker (5.26%) pay better than blackjack insurance.

Insurance isn’t the only bad blackjack side bet. In fact, you’ll find a number of other side wagers depending on the casino.

These are often tempting because the side bet leads to much bigger payouts than a normal game. But as a general rule of thumb, the house edge on these wagers is much worse than playing the game as normal.

5. Failing to Get Comps

Many beginning blackjack players, including myself, are naive about how you get comps. I personally thought that you simply start playing, and you’ll receive a free meal or better at the end of your session.

But the reality is that the pit boss must rate your play before you receive any good comps. Otherwise, the only thing you’ll get is a few free drinks.

The best way to ensure that you’re rated is by signing up for the player’s club first. You can either visit a casino’s player’s club desk in person or sign up online.

You’ll receive a player’s club card that can be used to get rewards for various casino games. You then hand this card to the blackjack dealer, and they’ll let the pit boss know that you’d like to be rated.

Another way to be eligible for comps is to bet higher stakes so that the pit boss notices you. This is less guaranteed, though, because you won’t technically know what bet sizes you must make for the pit boss to notice.

This is why I suggest taking a few minutes to join the player’s club and giving your card to the dealer.

Another point worth mentioning here is that blackjack comp rates aren’t very high. The reason why is because the casino doesn’t make much money off blackjack due to low house edge.

Here’s an example of the type of comps that you can normally expect:

  • Blackjack comp rate is 0.1%.
  • Blackjack house edge is 1.0%
  • Your bet $1,000.
  • Your theoretical comps would be $1.
  • Your theoretical losses would be $10.

Obviously earning a dollar in comps doesn’t begin to approach your theoretical losses. This is why you should never play blackjack just for the sake of earning more freebies.

You’re better off simply paying for your meal or hotel room, rather than grinding in blackjack games longer than you want to.

6. Counting on Betting Systems

Some blackjack players believe that betting systems can somehow overcome the house edge. And the most popular systems include the D’Alembert, Labouchere, Martingale, and Paroli.

All Betting strategies break down into two classes:

1. Positive progression – Increase bets during winning streaks.

2. Negative progression – Increase bets during losing streaks.

Negative progression systems are definitely riskier because you’re chasing losses with bigger wagers. But negative progressions also work, at least in theory.

Here’s an example using the Martingale, which calls on you to double bets following every loss:

  • You bet $10 and lose (bankroll at – 10).
  • You bet $20 and lose (bankroll at – 30).
  • You bet $40 and lose (bankroll at – 70).
  • You bet $80 and lose (bankroll at – 150).
  • You bet $160 and lose (bankroll at – 310).
  • You bet $320 and win (bankroll at +10).

The reason why the Martingale and other negative progression systems work is because you can always win back your losses, plus a small profit. But there are three main problems with using the Martingale in blackjack:

1. This system doesn’t overcome the house edge.

2. You’d need an infinite bankroll to win 100% of the time.

3. Table limits keep you from effectively using the Martingale.

The table limits are especially damning because it’s not hard to lose seven or eight hands in a row and reach the max bet. At the table max, you’re no longer able to effectively use your betting strategy.

If you’d like to try a betting system for fun, by all means do it. But just keep in mind that no betting set strategy will overcome the blackjack house edge.

7. Playing at a Table with a Continuous Shuffling Machine

Some blackjack tables use continuous shuffling machines (CSM) to speed up the game. This means the dealer doesn’t have to slow the action by reshuffling the shoe.

A CSM seems like a helpful device, but it actually increases your potential blackjack losses.

The reason why is because CSMs speed up play by around 20%. This means that if a blackjack table normally sees 80 hands per hour, you’ll be facing 100 hands per hour with a CSM.

Here’s a look at how this impacts your theoretical losses:

  • The house edge is 1%.
  • You bet $10 per hand at 80 hands per hour ($800 total).
  • Your theoretical losses would be $8 in this case.
  • You bet $10 per hand at 100 hands per hour ($1,000 total).
  • Your theoretical losses would be $10 in this case.

The reason why you and I play blackjack is to win. But it’s hard to ignore the fact that casinos have an edge on this game.

And the fewer hands you see, the less you’ll be exposed to the house advantage. This is why you should avoid any table that uses a CSM.

One more point worth adding is that you should also avoid blackjack tables with three or fewer players.

A sparsely populated table means that the dealer can speed up the game. And this leads to more hands per hour and higher exposure to the house edge.


Avoiding blackjack mistakes begins with looking over a strategy chart. This clears up many misconceptions on how you play certain situations.

Of course, there are a number of other big mistakes that you must avoid in order to win at blackjack.

These include not looking for good blackjack rules, taking insurance, not getting comps, over using betting systems, and playing at tables with a CSM.

If you can avoid these mistakes and find the best blackjack tables, then you’ll dramatically boost your chances of winning money.

Petko Stoyanov
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About Petko Stoyanov
My name is Petko Stoyanov, and I've been a gambling writer for more than ten years. I guess that was the natural path for me since I've loved soccer and card games for as long as I can remember! I have a long and fairly successful history with English Premier League betting and online poker, but I follow many other sports. I watch all big European soccer leagues, basketball, football, and tennis regularly, and I keep an eye on snooker, volleyball, and major UFC events.