Why not double?

[standard toaster]

On the Blackjack Double Down Outcome Probabilities chart on in the tournament section of the site it lists all the percentages of winning, pushing and losing from doubling the given hand. Many of the percentages will collide with basic strategy such as a9. Basic is to stand (we know this) but doubling is in our favor on dealers 2-9 with dealers six only winning 32.3% of the time.

With percentages in your favor in most instances why not double? In almost all soft hands there are cases where win% is higher than losing% why not double these that are not on the basic strategy chart?


now doubling a blackjack is stupid and may have never seen anyone even think of this but with percentages being as low as 29.9% against you why not take it? even though you will lose sometimes wouldent it be to your advantage to double in the long run?

doubling 11 on a dealers ace with peek why not?

granted you will not win over 50% but you still win more than you lose



finally doubling stiff 8 and 9s

why not double 8 on dealers 5 and 6
why not double 9 on dealers 2?

 

[bjcount]

why not double 8 on dealers 5 and 6
why not double 9 on dealers 2?

If you are using BS to play, then you will never know when you have the advantage to DD the hands you ask about. I regularly DD with index plays all those you mentioned. A-9 vs 4,5,or 6 is a bit tricky. I'll do it in the general pop area but never in High Limit. The dealers voice travels across the room when they call out "doubling soft 20"!

BJC

 

[standard toaster]

If you are using BS to play, then you will never know when you have the advantage to DD the hands you ask about. I regularly DD with index plays all those you mentioned. A-9 vs 4,5,or 6 is a bit tricky. I'll do it in the general pop area but never in High Limit. The dealers voice travels across the room when they call out "doubling soft 20"!

BJC

But these statistics are without counting... although i count im just making the arguement here. If in the long run statistics show these are advantage points for the player why do we not implement them into the basic strategy card?

 

[moo321]

You're not including the value of standing. Doubling wins money, but standing wins more.

 

[callipygian]

With percentages in your favor in most instances why not double?

Because you give up the option to hit again if you don't pull the card you want the first time.

If you double hard 8 (vs. dealer 6) and get dealt a 3, you're stuck with an 11. That's not a bad scenario, but if you hit hard 8 (vs. dealer 6) and get dealt a 3, you can hit again.

If you hit hard 11 (vs. dealer A) and get dealt a 5, you can hit again. That's not a good scenario, but it's better than doubling hard 11 (vs. dealer A), drawing a 5, and being stuck with 16.

 

[ihate17]

Doubling blackjack==what you are not taking into consideration

Somehow I think doubling down on blackjack just might be the worst bet in the casino, even if you win it more often than lose.

If you have $100 bet, you are paid $150 on your blackjack.
Instead you decide to double??? Now you are going from a NO RISK situation because if you can double your blackjack, the dealer does not have blackjack so you are guaranteed 150% payout.
Instead you now are willing to risk 200% of your original and now no risk bet, to win just another 33%. You need to win 80% of these to break even with your non doubling blackjack profits.

Now in a tournament there is a time where you will do this because you must get more money on the table.

ihate17

 

[callipygian]

You need to win 80% of these to break even with your non doubling blackjack profits.

I think it's higher. If you consider a flat 5% probability on tying a hand ...

EV(BJ) = +1.50
EV(double) = 2*W-2*(0.95-W) = 4*W - 1.9 = 1.5
W = 0.85

 

[Renzey]

The Best Alternative

On the Blackjack Double Down Outcome Probabilities chart it lists all the percentages of winning, pushing and losing from doubling a given hand. Many of the percentages will collide with basic strategy.
With percentages in your favor in most instances why not double?

Your correct play is always determined by comparing the results of each alternative. With many hands, you make money long term when you double. But with lots of those, you make more money long term when you just hit.

A clear example is when you have 9 against a 7. If you double, you win 53% of the time (counting pushes as a half win and a half loss, which simplifies the evaluation process, yet keeps it accurate). But if you just hit, you win 59% of the time (handling pushes in the same way). Even though doubling wins 53% of its 2 unit bets (while losing 47%), just hitting and winning 59% of its 1 unit bets (while losing 41%) still makes more money.

So to make doubling down the best play, doubling has to make more money than playing that hand any other way -- not just win more often than it loses.

 

[BlodiaInc]

Not to get off topic, but...

Mr. Renzey... it is great to see you back... I hope everything is well with you and your family.