Why spread
- Thread starter rmi227
- Start date
sagefr0g
Well-Known Member
the low bet or no bet is the way to go when you do not have the edge but if you only have one other higher bet for when the odds are in your favor you may end up either underbetting or overbetting the advantage. better to have proportional bets that fit the advantage according to the true count.rmi227 said:
sagefr0g
Well-Known Member
right an edge is an edge. realize though that even with an edge in blackjack one doesn't always win ones bet placed at an advantage due to normal fluctuation that is inheirent with respect to winning and losing a given blackjack hand. also realize that the advantage stems from the relative proportion of aces, faces & tens to the 2's, 3's, 4's, 5's & 6's. the greater the ratio of high value cards to low value cards that are left to be dealt the greater the advantage. so not all advantages are the same.rmi227 said:
which would you rather do bet $100 at a high advantage or at a much lower relative advantage? keep in mind that you may well lose the bet even at the high advantage.
also the idea of what is overbetting or underbetting needs to be considered with respect to what level of risk you are willing to gamble with. there is an optimal level of betting that can be modeled after a math equation called Kelly betting that can help quide your decisions about what the appropriate way to bet is.
EasyRhino
Well-Known Member
I wish there was a newbie guide on proportional betting in a FAQ or something, but I don't know where one is.
If you're just trying to make money, in a vacuum, you'd want to bet the absolute minimum whenever you don't have an advantage, and then gillions of dollars whenever you have any sort of advantage. The problem is, we're human, and have limited bankrolls. If you bet too much with too small of an edge, you're going to hit a string of bad luck and lose everything.
It's been proven that optimum long-term bankroll growth occurs when you bet in proportion to your bankroll size. The formula is (bankroll)*(your edge)/(variance). Blackjack is a low-variance game, so it's something like bankroll*edge/1.2.
In other words, if you have a 1% advantage at a particular count, you should bet a little less than 1% of your total bankroll. If you have a 2% advantage at a different count, you should bet a little less than 2% of your bankroll.
Even with this scheme, if you pick your bet amount, and stick with it, (for instance, $10k bankroll, $10 bets with a 1% advantage) there is still a significant change of losing it all, around 16%. In fact, if you bet double what the optimum bet is calculated, then your risk of ruin is a guaranteed 100%. (I don't know why this is. Magical math stuff)
This is why people with nonreplenishable bankrolls, usually bet substantially less than "optimum", for risk management.
The quick rule of thumb is to figure out what your bet max bet is given your bankroll, and then work out the details on your min and spread from there.
If you're just trying to make money, in a vacuum, you'd want to bet the absolute minimum whenever you don't have an advantage, and then gillions of dollars whenever you have any sort of advantage. The problem is, we're human, and have limited bankrolls. If you bet too much with too small of an edge, you're going to hit a string of bad luck and lose everything.
It's been proven that optimum long-term bankroll growth occurs when you bet in proportion to your bankroll size. The formula is (bankroll)*(your edge)/(variance). Blackjack is a low-variance game, so it's something like bankroll*edge/1.2.
In other words, if you have a 1% advantage at a particular count, you should bet a little less than 1% of your total bankroll. If you have a 2% advantage at a different count, you should bet a little less than 2% of your bankroll.
Even with this scheme, if you pick your bet amount, and stick with it, (for instance, $10k bankroll, $10 bets with a 1% advantage) there is still a significant change of losing it all, around 16%. In fact, if you bet double what the optimum bet is calculated, then your risk of ruin is a guaranteed 100%. (I don't know why this is. Magical math stuff)
This is why people with nonreplenishable bankrolls, usually bet substantially less than "optimum", for risk management.
The quick rule of thumb is to figure out what your bet max bet is given your bankroll, and then work out the details on your min and spread from there.
sagefr0g
Well-Known Member
if you have excell then Sonny's bet spread calculator should help:jee_pack said:
http://www.blackjackinfo.com/bb/showpost.php?p=15578&postcount=6
positiveEV
Well-Known Member
I just used Sonny's spreadsheet. Let's say you play a 6D H17 DAS LS, bet $10 when the true count is under 1 and bet $300 (30 units) when the true count is 1 or more.
Here are the expected results:
Hand Standard Deviation: 19.32 or $193.23
Hourly Standard Deviation: 193.23 or $1,932.33
Expected Value: 11.40 Units or $114.00
Risk of Ruin with a $15,000 bankroll: 39.97%
So you would win $114 per hour, more or less $1,932.33! Your EV would be very high for a $10 unit but so would be your variance. It could work pretty well with a huge bankroll in a casino that's clueless about card counting (or with an awesome act), but I doubt it would last long in any casino and you would play less hands than required to overcome the variance.
Here are the expected results:
Hand Standard Deviation: 19.32 or $193.23
Hourly Standard Deviation: 193.23 or $1,932.33
Expected Value: 11.40 Units or $114.00
Risk of Ruin with a $15,000 bankroll: 39.97%
So you would win $114 per hour, more or less $1,932.33! Your EV would be very high for a $10 unit but so would be your variance. It could work pretty well with a huge bankroll in a casino that's clueless about card counting (or with an awesome act), but I doubt it would last long in any casino and you would play less hands than required to overcome the variance.