Question for statistics people about 6 to 5 Blackjack

[Jumboshrimps]

Is doubling down on blackjack the proper move where the dealer shows 2 through 6? I was doing this the other night in Vegas and two pit bosses were arguing over whether it provided a player advantage. If it does provide a player advantage, I would be interested in knowing how much.

[weavin42]

I think it would be a very bad idea. I'm going to assume this is a single deck game and H17. If you look at the EV chart here http://www.bjmath.com/bjmath/ev/1dh17.htm
the largest EV for doubling an 11 is +.73 (7,4 vs dealer 6). I can only assume without doing any real math or sims that the fact that you are holding one of the 16 10-value cards in your hand that the EV would be much less. Compare this with the 1.2 EV payout on the natural and it would make a bad game worse. With that said, I'm sure there exists a high positive count where doubling the hand is better than the 6:5 payout but if you are counting why would you play this game anyway?

[shadroch]

I asked this a year or more ago and Ken Smith answered with the math that showed it was a bad idea. Besides,many casinos won't let you,from what I've been told.If you have any sort of choice,avoid these games.

[Automatic Monkey]

It's not unbeatable and under the right conditions it's better than a poor shoe game, for counting as well as other techniques. But I have yet to see a casino where the 6:5 SD was better than the shoe. Don't mess with it until you are very experienced.

There is a count where doubling the hand is better than taking the 6:5 natural but it's probably not worth it for reasons of heat and variance.

[Kasi]

Originally Posted by Jumboshrimps

Is doubling down on blackjack the proper move where the dealer shows 2 through 6? I was doing this the other night in Vegas and two pit bosses were arguing over whether it provided a player advantage. .

As others already said, at least for a BS player, it's an absolutely horrible play and still would be even if BJ paid 1-1 instead of 6-5 in any game with any rules against every dealer upcard.

I think so anyway lol.

[tedloc]

Originally Posted by Jumboshrimps

Is doubling down on blackjack the proper move where the dealer shows 2 through 6? I was doing this the other night in Vegas and two pit bosses were arguing over whether it provided a player advantage. If it does provide a player advantage, I would be interested in knowing how much.

Let's take some real numbers and use the worst card for the dealer (6). If you bet $5 and get this hand 100 times, you will win $600 ,if you keep the Blackjack. If you double down against the 6, you can expect to win the hand 73-75 times. If you win 75 times($750), you loose 25($250) for a net gain of $500. TAKE THE BLACKJACK

[Renzey]

Originally Posted by Jumboshrimps

In a 6-to-5 game, is doubling down on blackjack the proper move where the dealer shows 2 through 6?

Wong's EV tables from Professional Blackjack show doubling down with A/10 vs. a dealer's 6 (the optimum situation) as a +68% EV (single deck, H17). This is the mathematical equivalent of winning 84, losing 16 and pushing zero out of 100 -- for a net averaged profit of $68 per hand on a $100 bet. But if you just take the 6-to-5, you'll average $120 per hand. Not close.