Those little blackjack mistakes add up

I just returned from a Caribbean cruise. One of the men at our evening dinner table was also a frequent blackjack player in the casino, and I mentioned I had written a blackjack book.

One morning, the two of us kicked back on the sun deck and discussed various strategy points in the game. I had already seen him make the mistakes of a typical player, and he wanted to know what was wrong with them.

Even Money: Our first topic was taking Even Money on blackjack, which he had always done. I explained that when the dealer has an Ace up against your blackjack, she's got almost exactly four chances out of 13 to have a 10 in the hole.

So say you bet $20 and have blackjack against an Ace 13 times. If you always take Even Money, you'll collect $20 all 13 times for a total payoff of $260. But if you let it go, you'll push those four times the dealer has the 10 underneath -- then get paid $30 the other nine times for a net payoff of $270! This is just a sample cross-section of how you'll do each way with all those blackjacks over your lifetime.

Although the difference boils down to a little less than a dollar per hand, you'll generally be dealt about 85 hands per hour. This is only one mistake. It's typical for a $20 bettor to throw away $20 per hour in pure mistakes!

11 against a Face: My new friend also didn't double down with 11 if the dealer showed a 10. Fact is, if you just hit your 11 against a 10 up, you'll go 39/31 after you have this hand 70 times (adjusted for pushes). But if you double down and buy a small card, you'll be stuck standing on a "stiff" (12 through 16). Perhaps surprisingly, that'll merely reduce your overall won/lost record to 38/32.

Now think it over. Winning 39 and losing 31 at $20 apiece earns $160 net. Winning 38 and losing 22 at $40 each earns $240! That's 50 percent more net profit on the fourth best starting hand you can be dealt. But it's only the fourth best hand if you optimize all its potential!

Ace/Tiny vs. Tiny: Like most players, he didn't differentiate between hands like A/3 against a 3 -- and A/6 against a 6. I explained the key difference.

When you take one hit to any hand from A/2 through A/5, there are only five cards out of 13 that will give you a "made" hand (17 through 21). So eight times out of 13, you'll be stuck with a stiff, needing a dealer bust.

But when you have A/6 or A/7, it's exactly reversed! Now you'll make a completed hand eight times out of 13. Since you won't need a dealer bust nearly as often, you should double down much more aggressively with A/6 and A/7 (do it against 3, 4, 5 or 6). But with the "Ace/Tiny" hands like A/2 or A/3, you need the dealer to be showing her very weakest up-cards (5 or 6). As a general guide, just remember this rule of thumb; Ace/Tiny against a Tiny is a bad double.

12 against a "13": Here's a misnomer that gets most players into a world of trouble. Incorrectly assuming the dealer has a 10 in the hole, they look at their 12 against a 3 and call it "12 against a 13."

If it really were 13, then yes, you should really stand. The truth is that 70 percent of the time, the dealer will have some other card in the hole! If you stand, you'll need a dealer bust -- or you're dead. And with a 3 up, the dealer busts just 37 percent of the time. Hit that hand!

Fix these and the other slew of mistakes you're probably making, and you'll save one whole bet an hour, on average.