stdev < 1 in CVCX Wong in and flat bet

**Charlie Mosby** · 08-25-2013, 11:34 PM

Hi,

I just noticed that the standard deviation is smaller than unity in the situation as shown in the picture.

The bet size is 2*$50 = $100, and the stdev per round is ~$96. (at the bottom, lower left to the green bell curve)

Flat betting with basic strategy at TC 0 has a unit stdev of ~1.15, and from the count-wise table the stdev is only higher at positive counts (with index play and all that).

How could this be? Is it because the correlation between the simultaneous two spots?

I don't think this is due to the specific set up with this sim.

Thanks.

**Charlie Mosby** · 08-25-2013, 11:36 PM

oh darn, how do I maintain the resolution of the picture I uploaded? Oops.

Let me try this.Example_01.png Example_02.png

**Norm** · 08-26-2013, 03:47 AM

78% of time you're betting zero.

**Three** · 08-26-2013, 04:57 AM

Originally Posted by Norm

78% of time you're betting zero.

Making 78% of your bats at 0 variance will certainly limit SD.

**Nyne** · 08-26-2013, 01:47 PM

Originally Posted by Norm

78% of time you're betting zero.

I know it's your software, but that doesn't seem to be the cause of what Charlie is seeing. Just as a quick test, I pulled up a sim for hilo full indices and set it to flat bet (spread=1) and play only positive counts. As I changed the back-counting point, the standard deviation reported at the bottom didn't change much. Moving it up past +5 brought the SD up above 1.0 times the total bet, but the change was gradual. If it were changing primarily based on the percentage of hands played, it would be moving down quickly, not up slowly. Charlie, I believe the answer to your question is that the standard deviation reported in the big grid is the standard deviation for a single hand (you can see that unchecking "play two hands" doesn't affect this), and the standard deviation at the bottom of the window is the total SD for both spots, which is in the ballpark of what would be expected based on this link: http://wizardofodds.com/games/blackjack/appendix/4/. Per that link, for play-all, the SD should be about $50*sqrt(2)*1.34942=$95.42 (this number is for a different rule set than you are using, but it should be fairly close).

**Norm** · 08-26-2013, 02:40 PM

There are two ways of doing Wonging with CVCX -- pre-sim and post-sim. They react a bit differently. Wonging can only be estimated post-sim. I put the post-sim feature in the first version of CVCX because BJRM had it. But, it's not accurate in either product. The pre-sim wonging was added later and is accurate.

**Nyne** · 08-26-2013, 02:47 PM

Would I be correct to assume that what Charlie and I are looking at is the post-sim version? I'm still using version 4.0.186. I'm aware that this is an estimate, but when playing with a low risk of ruin, I consider it "close enough."

**Norm** · 08-26-2013, 02:54 PM

I believe so.

**Charlie Mosby** · 08-28-2013, 07:06 PM

oh, I didn't know only pre-sim-Wonging is accurate.....yeah I thought I noticed some differences between the two but I just concluded that I messed up the configuration.

Thanks Nyne, I did what you said, turning the wonging point, the 2-spots, etc, and now the numbers make perfect sense; I do see the ~1.15 now, the sqrt(2), and the effect of zero bets.

I think I didn't manage my sims very well and was looking at some pre-sim-Woning results along with this, and I got very confused.
yeah this one has post-sim wonging.

Reverse-engineering CVCX is quite a challenge :P

Thanks.