Need Blackjack Double Down Statistics

I just can't seem to find the right information on what I'm looking for in regards to statistics on doubling down.

I know that in normal and random blackjack play, the player should expect to win about 58% of his double downs. However, HOW OFTEN should a player expect to ENCOUNTER a double down play? How frequent should a double down opportunity come up?

At the latest online casino I've played, I've encountered about 220 double down opportunities in about 2200 hands of blackjack. So that means I've encountered a double down opportunity in 10% of my hands. Is this normal frequency of double down opportunities?

You will encounter a dd opportunity 9.67% of the time, splits about 1.8%.

That's normal. Assuming DOA, DAS, 6D, basic strategy, you should double 10.1% of the time. You should win about 55% of these.

As to why I'm asking this question, of the 220 double downs mentioned above, I've won only 50.9% (Vegas Strip Blackjack, 4D game). I did worse on the "big money" hands of $60 or above, only 42%. I suspected the casino employed a strategy of creating excessive losing double downs in order to catch my big money wagers. They were successful, I've lost nearly $8,000 there. It appears as far as frequency of double down encounters, it is normal.

In absence of other evidence, I would definitely chalk this up as just being due to the small sample size. 55% wins would be 121/220. Your 50.9% figure means you have won 112 hands. That is only 9 hands away from expectation. With a probability of success of p=0.55, the probability of winning 112 or fewer of 220 trials is about 12.5%. That's certainly no fun, but it's also not particularly uncommon. While you won a smaller percentage of hands with the larger bets out, obviously your sample size for those hands is even smaller. You didn't state how many hands were included in that sample, but assuming 50 hands with 21 wins, your odds of doing that poorly are around 4.4%. Again, that's bad, but not unheard of. If your big hands number less than 50, the odds of winning 42% or fewer is even higher. Looking at it another way, given that you were unlucky enough to win 21 of 50 with big bets out that means that you won 100/170 of your other double downs. You will only win 100 or more out of 170 17.8% of the time. You were actually pretty lucky on your smaller bets. I know it doesn't make your losses any more fun, but the point I'm trying to make is your sample size is just too small to conclude that you are playing anything but a normal fair game.

I'm stunned at how much analysis people are willing to put into a negative expectation online game.

Maybe they're cheating. Most likely they aren't. Either way you're going to lose your money, how long it takes is the only variable.

Did you ever get your money out of Cipher?

Where you doubling down on hands like A-3 vs a 3? A lot of people miss double down on soft hands.

No, not a dime. His wife is a court reporter in Visalia CA while the supposed District Attorney who was supposed to "investigate" Cipher works in the same building so they know each other. Doesn't surprise me that the DA didn't do any work at all on it.

A-3 vs. 3 in particular, I don't double down but a A-3 vs 5 I do double down. I usually play Vegas Strip blackjack with 4 decks.

A3 vs. 3?

I play 6 decks more often than not so this is according to 6 decks--- You DON'T double down an A,3 against a dealer 3. Off the top of the shoe it's:

.049873 if you hit
-.00337 if you double

This is a difference of .05237 in the wrong direction unless the TC is around +mega off the chart (+10TC or more) and then you overcome this gap in the wrong direction (that you didn't have to cause for yourself by doubling) to have an advantage in doubling an A,3 against the dealer 3. You still have this "gap" and take the more dangerous road by doubling it.


Hang on let me dig some of this out for you. It is all buried in stacks and stacks of crap around here. There is more to it than a cut and dry table since you have to compare the standard percentages of differences to TC. I have some very extensive tables of percentages on this subject someplace. It's also not a "cut and dry" thing but based on count that you would deviate from normal strategy, so you have to weigh out more than one table of stats against each other. Also bear in mind that all my "ready reference" information presented here is based on 6 decks, not 4. This could be slightly different for 4 decks but not by much.

I am thinking you could compare a win, loss and tie percentage based on TC to an Expected Value Table and work out a happy medium for index play calculation (what I do for Gordon/DHME/Tarzan system). This throws in a THIRD variable, the type of count also but that makes it all nuts to pick apart and I doubt you have the desire to evaluate this for the next two and a half years, using a count that would be like a foreign language to you (I take into account 2-5's, 6-9's, 10's, A's in four separate groups so can have a different index play with the same TC!). I have a regular expected value table someplace or someone else could slap one up here, either or.

This all brings me back to my original thought process which is, "You don't double down an A,3 against a dealer 3".

Those soft doubles are not as spiffy as you may think!

Percentage of double down possibilities if you take every single opportunity to do so is about 17.8% of your hands in a DOA situation (I found some notations about this while digging about). That could swing in either direction obviously since cards by their nature have randomness. Here's the thing though... not all those double downs, especially the soft ones are all that great and you might not be in as good of shape as you may think with them! One author, I can't recall who (possibly Wong?) wrote a great deal on this and "risk aversion" play since some of these doubles have such a tiny difference (in the very long haul but not in the short term) between doubling and NOT doubling. In the following chart you will plainly see why it is to your disadvantage to veer off the basic strategy chart unless you have a count related reason to do so and also how in some instances the soft doubles offer so little of a difference in the long haul that risk averse play would dictate not taking a few of them.


A little something I notice and realize now... you mention ONLINE casinos. OOPS! Throw the count right out the window. I don't play online blackjack... I am just not that trusting a soul, what can I say! I don't think there is any getting around the house advantage in online casinos; Maybe I am wrong but I doubt it.


6D,S17,DOA,DAS=HA of Approx. .4%

Player/ Dealer / Hitting / Doubling
_____ ______ ______ ________

A,2 / 2 / .045498 / (.06661)

A,2 / 3 / .073677 / (.00077)

A,2 / 4 / .103706 / .068041

A,2 / 5 / .137333 / .139852

A,2 / 6 / .162671 / .187925

A,3 / 2 / .021511 / (.06721)

A,3 / 3 / .049873 / (.00337)

A,3 / 4 / .08174 / .066904

A,3 / 5 / .115726 / .138428

A,3 / 6 / .140226 / .186374

A,4 / 2 / (.00191) / (.07088)

A,4 / 3 / .028141 / (.00528)

A,4 / 4 / .059395 / .062389

A,4 / 5 / .094352 / .133708

A,4 / 6 / .118402 / .182917

A,5 / 2 / .02283 /(.00395)

A,5 / 3 / .007133 / (.0091)

A,5 / 4 / .039363 / .058627

A,5 / 5 / .074608 / .129043

A,5 / 6 / .101516 / .185557

Cipher

That's a name I haven't heard in a while! I am sure that he is still at it, scamming away on any unsuspecting victim he can. Your only hope is to retain an attorney in California and live with the $225 an hour in a civil suit. If he is "connected" in his home turf as you say, then getting them to press criminal charges is out the window. He is probably having the DA over for tea and crumpets and they are laughing about it all.

How long has it been with that? I am still amazed how you (or much of anyone for that matter) got sucked into this scam after seeing his "demonstration videos". I wrote a few lengthy words on what I thought of Cipher and his "amazing system" way back at some point. Could have been worse and you could have invested the 1 million minimum with Bernie Madoff?