MaceFremonti
MaceFremonti
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Joined: Oct 15, 2012
October 27th, 2012 at 5:07:02 PM permalink
Is it possible to figure out what the average length of a player's winning and losing streaks would be based on house rules and player strategy -
i.e. WW L WW LL WWPWW L W L W L - average win streak of 2 hands and average loss streak of 1.2 hands - ignoring pushes?

If anyone would like to tackle this in a simulator for me the setup is

play standard applicable basic strategy
6 decks
Dealer stands on soft 17
Double any two cards
Double after split
No resplitting
Split Aces get 1 card
Late surrender

TX!
MangoJ
MangoJ
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October 27th, 2012 at 11:43:53 PM permalink
This question doesn't really need any specific rules.

If p is the probability of an event (say, a winning hand), then p^N is the probability of this event happening N times in a row.

The average number of N is then:
<N> = sum_N N*p^N / sum_N p^N
doing the (boring) math: sum_N N p^N = p / (1 - p)^2, sum_N p^N = 1 / (1 - p)
So the average number of consecutive events is <N> = p / (1 - p).

In blackjack you win 42.4% of your hands, and lose 49.0% of your hands (the rest are pushes). So if you ignore pushes, you end up with
average Win sequence: p=46.4%, <N> = 0.86
average Loss sequence: p=53.6%, <N> = 1.16

Edit:
If you only count sequences from 1 (i.e. you don't identify LL as a win sequence of length 0), then you need to sum the sums_N from N=1 to infinity.
In this case you get <N> = 1 / (1 - p). Then the average win sequence lasts exactly 1 longer, so <N> = 1.86 and <N> = 2.16.
98Clubs
98Clubs
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October 28th, 2012 at 12:02:37 AM permalink
I've always used a simple and fairly acurate estimation...

Win = 3/7 (0.4286)
Tie = 1/12 (0.0833)
Lose the remainder (0.4881)

Win / (Win+Lose) = 0.4675
Some people need to reimagine their thinking.
MangoJ
MangoJ
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October 28th, 2012 at 12:21:25 AM permalink
The numbers are from the Wizards Blackjack Site. I think Appendix 4.
MaceFremonti
MaceFremonti
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October 28th, 2012 at 5:57:25 AM permalink
TX f/the quick answer!
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