DRich
DRich
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January 12th, 2022 at 5:59:15 AM permalink
Quote: Romes

It's good to have fun, but if you love math you should never double for less, because you're just literally giving up money when you're in an advantageous position =)... assuming correct doubling strategy of course.



Are you saying mathematically it is wrong to double down for less even if you have most of the bet? eg. $100 BJ bet get 8,3 vs 5 but you only have $95 left. Would that be wrong? My guess is no, but doubling down for $5 would be wrong. What percent of the wager would you have to have to make doubling the proper play?
Order from chaos
SOOPOO
SOOPOO
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January 12th, 2022 at 7:28:03 AM permalink
Quote: DRich

Quote: Romes

It's good to have fun, but if you love math you should never double for less, because you're just literally giving up money when you're in an advantageous position =)... assuming correct doubling strategy of course.



Are you saying mathematically it is wrong to double down for less even if you have most of the bet? eg. $100 BJ bet get 8,3 vs 5 but you only have $95 left. Would that be wrong? My guess is no, but doubling down for $5 would be wrong. What percent of the wager would you have to have to make doubling the proper play?
link to original post



In your example of an 11 versus a 5, since you are at the advantage, and will never take a second card, you should double even if it is just for an extra penny. It gets complicated if you have hands like a 9 total versus a 5. Since by doubling you are giving up the extra card you will be taking if you draw a deuce, that has to be factored in. Soft hands can also have that type of complexity.

EditÖ. the main point really should be if you place a BJ bet and canít deal appropriately with the need to split and/or double, you shouldnít be betting that much!
mwalz9
mwalz9
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January 12th, 2022 at 8:01:06 AM permalink
The double for less was the only money I had on me. I was all-in at the time.

The dealer wouldn't have stopped the game to let me run to the ATM.
SOOPOO
SOOPOO
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January 12th, 2022 at 8:37:16 AM permalink
Quote: mwalz9

The double for less was the only money I had on me. I was all-in at the time.

The dealer wouldn't have stopped the game to let me run to the ATM.
link to original post



Thatís my point! If you donít have enough for a simple double down donít make the bet! ButÖÖ. Congratulations!
ksdjdj
ksdjdj
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January 12th, 2022 at 2:46:39 PM permalink
Quote: mwalz9

The double for less was the only money I had on me. I was all-in at the time.

The dealer wouldn't have stopped the game to let me run to the ATM.
link to original post


Here is how I would work the "cut-off" figures for "doubling for less":

1: Use a site like >>> https://wizardofodds.com/games/blackjack/hand-calculator/ <<< to work out the "hit value" and "double value".
2: Divide the "double value" by 2
3: Take the value from "Step 2" away from the "hit value"
4: Divide the "Step 3" figure from" from "Step 2" figure.
5: Multiply the value calculated from "Step 4" by your initial bet to work out whether you should double for less or hit (see example for more details)

Example: Player 8-3 (11) vs Dealer 10, and $100 initial bet

Rules 6-Deck, Dealer Stands on Soft 17 and Hole Card Rule: "American" (other rules not relevant, for this example)

1: The hit value is: +0.117850 , and the double value is: +0.176919
2: 0.176919 / 2 = 0.0884595
3: 0.117850 - 0.0884595 = 0.0293905
4: 0.0293905 / 0.0884595 = 0.332248....
5: This means that you should double for less if you can bet an additional $33.23*** (or more^^^) on that hand and you should hit if you have $33.22*** (or less) available.

***: Most "live tables" I play at make you bet in units of $5, so the "real world cut offs" would probably be $35 or more (you should double "what you have available") and $30 or less (hit).

^^^: Although, always make full double bets when BS says to whenever possible (in other words, try to bet small enough on the initial bet, so that you have enough to "make the full double").
Last edited by: ksdjdj on Jan 12, 2022
Romes
Romes
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January 13th, 2022 at 4:28:48 PM permalink
Quote: SOOPOO

Quote: mwalz9

The double for less was the only money I had on me. I was all-in at the time.

The dealer wouldn't have stopped the game to let me run to the ATM.
link to original post



Thatís my point! If you donít have enough for a simple double down donít make the bet! ButÖÖ. Congratulations!
link to original post

Exactly. I would never bet anything I couldn't fully double, thus giving up EV/edge.
Playing it correctly means you've already won.
unJon
unJon
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January 13th, 2022 at 7:25:53 PM permalink
Quote: Romes

Quote: SOOPOO

Quote: mwalz9

The double for less was the only money I had on me. I was all-in at the time.

The dealer wouldn't have stopped the game to let me run to the ATM.
link to original post



Thatís my point! If you donít have enough for a simple double down donít make the bet! ButÖÖ. Congratulations!
link to original post

Exactly. I would never bet anything I couldn't fully double, thus giving up EV/edge.
link to original post



I bet thatís not true. If you happened to run out of the bankroll in your pocket during a good count and only had 2.6 max bets on you, do you:

1) bet because itís still plus EV or
2) not bet because you might have to split and get a double that you couldn't play in full?

ETA: I guess thereís a reasonable #3 of betting less than a full bet, but my gut says thatís less EV+ Be an interesting math problem to solve for optimal bet size for this ultra rare situation
Last edited by: unJon on Jan 13, 2022
The race is not always to the swift, nor the battle to the strong; but that is the way to bet.
Romes
Romes
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January 13th, 2022 at 11:45:20 PM permalink
I bet it is true =). Even back in just my blackjack days I used to calculate out my EV, estimate number of hours, and 3SD's and bring that much to have. Next, whenever that odd day came and I came up short and fell short, I would resize bets appropriately. Again, on that "last hand" I still wouldn't be betting anything I couldn't fully split and double down.
Playing it correctly means you've already won.
Hunterhill
Hunterhill
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January 14th, 2022 at 12:43:13 PM permalink
This can be further expanded on . What to do if you are on a trip and running out of money. Do you cut down on your bet sizes and try to grind it out for the remainder of trip? Or should you bet as normal and risk running out of money. I believe Grosjean analyzed this and determined that you should bet as normal and not cut down on bet sizes.
The mountain is tall but grass grows on top of the mountain.
Romes
Romes
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January 14th, 2022 at 3:06:18 PM permalink
Quote: Hunterhill

This can be further expanded on . What to do if you are on a trip and running out of money. Do you cut down on your bet sizes and try to grind it out for the remainder of trip? Or should you bet as normal and risk running out of money. I believe Grosjean analyzed this and determined that you should bet as normal and not cut down on bet sizes.
link to original post

It's going to come down to EV really. How small do you have to resize? If you have the funds to replenish on the next trip then I agree the EV is higher to continue betting as though you have your full bankroll. You just might have to also understand that if you do fall short and bust, you're also going to be losing table hours and hands that you could have played at a reduce rate the rest of your trip... so if this is day 2/5, that might be something to consider to resize, whereas if it's day 4/5 or 5/5 then yeah I'd keep shooting the full bets as long as possible.

...and still leaving enough on the last hand to split/double =D.
Playing it correctly means you've already won.

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