charliepatrick
Joined: Jun 17, 2011
• Posts: 2512
March 29th, 2015 at 2:41:46 PM permalink
Please forgive me but I am wondering whether anyone can give me some general advice on protecting a multi-deck game from countability and how one can measure it at the design stage or do you just ask the casino to use a CSM?

I'm designing a Blackjack based game, as normal you're trying to beat the dealer without going bust, but it seems Aces have a large effect on the edge. The basic House Edge comes out (using six decks) at 1.61%, but removing just one ace (i.e. 23 rather than 24) increases it to 1.83%, whereas removing a 5 decreases it to 1.54%. Based on wizard's analysis of Blackjack ( http://wizardofodds.com/games/blackjack/appendix/7/ ) it seems this game is more suspect to card removal.

Obviously Blackjack starts from a smaller number, so statistically sometimes there can be an advantage (and counters detect this and take advantage). However (i) is 1.6% sufficiently high not to worry about it, (ii) is the difference of 0.22% for one card in 6 decks a concern, (iii) should I aim towards using fewer decks and an even lower HE?

Many thanks (ps hope to be at Coventry in May).
surrender88s
Joined: Jun 23, 2013
• Posts: 291
March 29th, 2015 at 8:19:07 PM permalink
Let us count :-)
"Rule No.1: Never lose money. Rule No.2: Never forget rule No.1." -Warren Buffett on risk/return
ssho88
Joined: Oct 16, 2011
• Posts: 583
March 30th, 2015 at 2:12:07 AM permalink
shuffle after each round :-)
CrystalMath
Joined: May 10, 2011
• Posts: 1907
March 30th, 2015 at 5:39:20 AM permalink
It seems that counting might be effective in this game, except it will be more volatile than counting blackjack. I would at least develop a hi-lo count and run simulations where you track how often you hit each count and what you won/lost at each count.
I heart Crystal Math.
charliepatrick
Joined: Jun 17, 2011
• Posts: 2512
March 31st, 2015 at 6:09:30 PM permalink
Many thanks for the excellent idea - it took a while to develop the program and iron out some bugs but I eventually managed to run 10 million shoes (338m hands) with 60% penetration (I have to assume the same player strategy all the time as it takes me ages to work it out). It got the House Edge from various small runs at nearer 1.66% (rather than the 1.61% I'd worked out). However it gave the following results.
`11.167% 10 - 3% House Edge20.236%  3 - 2% House Edge40.760%  2 - 1% House Edge19.811%  1 - 0% House Edge 6.659%  0 - 1%   advantage to player 1.266%  1 - 2.5% advantage to player 0.011% 2.5+%    advantage to player.`
Essentially unless only betting when the count is high (i.e. back-counting), the player would have to jump from a small bet of 1, to a large bet of 39, to show a long term profit. (I'm not sure what happens at larger counts as there were few instances).

Since I've never analysed Blackjack in similar detail, is this spread of advantages similar to that in Blackjack? I also think, starting from a higher initial House Edge, perhaps the count has to be relatively higher before the advantage kicks in.

Many thanks
CrystalMath
Joined: May 10, 2011
• Posts: 1907
April 1st, 2015 at 6:01:41 AM permalink
Do you have the return tracked by count? I'm not sure that is necessary because the return will follow the count even if you don't have the details of the count. At 60% penetration, I think a spread of 1 to 39 is too aggressive for counters and likely too volatile. I recommend trying this at different penetrations, including 4/6 and 5/6.

If you know the EOR for every card, then I would use that data to make a hi/lo count and track your simulation data by the count. This way, you can play with different bet spreads to see if it is profitable. if it takes a spread of more than 1 to 15 or 20, then you are probably safe. You can also recommend the maximum penetration and if they should disallow mid shoe entry.
I heart Crystal Math.
Romes
Joined: Jul 22, 2014
• Posts: 5534
April 1st, 2015 at 6:48:26 AM permalink
Quote: charliepatrick

...I'm designing a Blackjack based game... The basic House Edge comes out (using six decks) at 1.61%...

lol and casinos want to pretend we're the "thiefs." 1.61% basic house edge, how to protect that game? Sit on your ass and don't worry, that's an awful game and even the ploppies will figure it out. Shame on anyone promoting a 1.61% HE game as a game of "blackjack."
Playing it correctly means you've already won.
charliepatrick
Joined: Jun 17, 2011
• Posts: 2512
April 1st, 2015 at 7:41:32 AM permalink
Thanks - yes I keep a running count (based on the EOR figures and decks left in shoe) and store the results in an array for each count value. I tried your suggestion as it seems 5/6 penetration does give the counter more or a chance, the count-in-favour opportunities occur more often (nearly 16%) and the spread only needs to be 1-11 to make a profit. Like standard Blackjack the advantage gets to about 5% and then reduces as the count increases.
`Count	Exp	         Hands	-10	-0.051 518	 5047223	1.083 250%-9	-0.047 801	 6361648	1.365 356%-8	-0.043 355	 8391425	1.800 993%-7	-0.039 425	10641819	2.283 979%-6	-0.034 649	13902695	2.983 838%-5	-0.030 603	17812656	3.823 006%-4	-0.027 038	23857416	5.120 350%-3	-0.023 460	31098405	6.674 433%-2	-0.020 359	41997698	9.013 672%-1	-0.017 065	46196724	9.914 879%0	-0.013 885	72409988	15.540 848%1	-0.010 048	42054017	9.025 759%2	-0.006 821	30815677	6.613 753%3	-0.003 571	22640681	4.859 211%4	-0.000 762	17379906	3.730 127%5	0.002 896	13002403	2.790 615%6	0.005 705	10042215	2.155 290%7	0.008 840	 7617152	1.634 816%8	0.011 517	 6088367	1.306 704%9	0.013 893	 4639521	0.995 748%10	0.016 416	 3697202	0.793 505%11	0.018 748	 2832765	0.607 976%12	0.021 164	 2168712	0.465 455%13	0.021 803	 1920119	0.412 102%14	0.024 860	 1427668	0.306 410%15	0.024 584	 1081695	0.232 157%16	0.025 776	  876309	0.188 076%17	0.028 475	  719025	0.154 319%18	0.032 118	  542865	0.116 511%19	0.030 261	  415350	0.089 144%20	0.032 400	  348905	0.074 883%`
charliepatrick
Joined: Jun 17, 2011
• Posts: 2512
April 1st, 2015 at 7:54:46 AM permalink
Quote: Romes

Shame on anyone promoting a 1.61% HE game ...

You are right and agree that for a simple Blackjack variant I should be aiming south of 1%. btw the "ploppy" House Edge at the moment is about 2.5%.

My feeling is that I possibly need to introduce a bonus which counteracts the count and both reduces the House Edge and countability factor. I am very grateful for everyone's help. Thanks