Total Jerk: The Old Double Your Bankroll

[Total Jerk]

Having a discussion about a gambler taking $200 on blackjack and the best way to attempt to double your money and turn it into $400 or go bust trying.

My suggestion is bet $200 on a single hand. You have a .478 chance of doubling, else you go bust.

But some real "sharp" characters have pointed out that betting $200 means you cannot split or double down and so the house edge on a single $200 bet is higher, because you are basically playing a NOSPLIT, NO DOUBLE DOWN game.

They suggest betting $100 initally to insure being able to split and double, and then betting either half your bank again or 1/2 the amount needed to reach $400, which ever is less.

I have pointed out some bjmath stuff I found, showing that you don't want to double down if you have bet a large fraction of your bankroll, the fractional increase in EV of double vs hitting is offset by the decrease in the chance of winning THAT hand, since you have so much riding on it.

But to no avail. Seems making multiple bets with slightly less House Edge is far, far superior than eliminate the double down and split, and make it one hand. Only a fool would think otherwise.

So is the tried and true advice of BET IT ALL ONCE to double your bank, wrong? Should one grind out multiple bets of between 25% to 50% of bank to get the lower house edge and try to double that way? Opinions?

[Don Schlesinger]

> So is the tried and true advice of BET IT
> ALL ONCE to double your bank, wrong? Should
> one grind out multiple bets of between 25%
> to 50% of bank to get the lower house edge
> and try to double that way? Opinions?

This is a complicated question, and the answer isn't obvious. The optimal approach probably involves betting more than $100 but less than $200, keeping in mind that doubling for less is also permitted.

Don

[Don Schlesinger]

Something is clearly wrong with this part:

> They suggest betting $100 initally to insure
> being able to split and double, and then
> betting either half your bank again or 1/2
> the amount needed to reach $400, which ever
> is less.

Suppose you bet $100 and win. You now have $300 and need $100 more to reach $400, thus doubling your initial bank. When you write "betting half your bank again," I assume you mean "half of your original $200 bank, or another $100," which is fine. But then you add, "or 1/2 the amount needed to reach $400, whichever is less, and that part doesn't make sense to me. The amount needed to reach $400 is $100, and half of that is $50. If you have $300 and are trying to reach $400, why would you bet $50, when betting $100 still permits you to split or double?

Don