Did Thorp just have awesome pos. flux or what?

[SPX]

So I am of course familiar with the story of Thorp's Reno/Tahoe trip with Kimmel and supposedly in a period of about 72 hours (and we're presuming this isn't all play time) he more then doubled his bankroll from $10K to $21K.

Am I missing something here?

I know that blackjack in those days was a good bit more beatable, but does that explain how he could double his money in about a weekend?

 

[KenSmith]

If his overall edge was 2%, doubling a bank doesn't take long with Kelly or half-Kelly bets.

To keep it simple, let's imagine a flat-betting game with a 2% edge, 1.14 var, half-Kelly bets, $10K bank:

Your bet should be (($10K * 0.02) / 1.14) / 2 = $87.72 per hand
Your expected win per hand is $1.75.
Hands to double your bank without bet resizing: 5700
At 60 hands per hour, that's only 95 hours.

Now, I'm NOT saying he had a 2% edge, and this overly simplistic example uses flat-betting. Still, you get the point.

 

[ChefJJ]

My Stab At It

As stated in my post title, this is a guess at the answer: Yes.

I imagine that he had a good streak of things falling in line with his plan. But from what you read and see about the guy, he had definitely done a ton of research into the game...a foundation for what many of us are doing these days.

I wasn't playing BJ in those days for sure, but one could guess that the casinos' rules were pretty liberal compared to the conditions we see. Single deck games with dealers drawing down to the bottom, double on anything, etc. perhaps. With today's basic strategy being pretty much nonexistent then (educated guess), casinos probably didn't have much reason to tighten any rules...people gave the house quite an edge without a consistent playing strategy.

Just a guess!

good luck

 

[Guynoire]

I think in Thorp's day because no one really knew basic strategy, including the casinos, that the casinos gladly offered 1D S17, DOA, DAS with almost 100% pen. He could have beat the game flat betting and playing basic strategy but that would have taken longer.

 

[ihate17]

That game was available in Vegas back then

I think in Thorp's day because no one really knew basic strategy, including the casinos, that the casinos gladly offered 1D S17, DOA, DAS with almost 100% pen. He could have beat the game flat betting and playing basic strategy but that would have taken longer.

The game you describe was not available, I think, in Reno back in the day but could be found in Vegas and against basic strategy the player had an advantage going in.

ihate17

 

[zengrifter]

The game you describe was not available, I think, in Reno back in the day but could be found in Vegas and against basic strategy the player had an advantage going in.

Only at Caesars. zg

 

[EasyRhino]

Besides playing a better game (nearly 100% pen, etc). He also might have been overbetting his bankroll. While Beat the Dealer does make some discussion of risk of ruin, I don't remember it as developed as you'd see nowadays.

No idea what his bet sizing was like on that trip.

 

[sagefr0g]

Besides playing a better game (nearly 100% pen, etc). He also might have been overbetting his bankroll. While Beat the Dealer does make some discussion of risk of ruin, I don't remember it as developed as you'd see nowadays.

No idea what his bet sizing was like on that trip.

thats my suspicion. i mean yeah he was on to something and knew darned well what he was doing but i'm not sure he realized how lucky he was or at least i don't think he let on about it. i mean after all he didn't play all that many rounds in his stories to have more than anecdotal evidence far as i know.

 

[SPX]

I wasn't playing BJ in those days for sure, but one could guess that the casinos' rules were pretty liberal compared to the conditions we see. Single deck games with dealers drawing down to the bottom, double on anything, etc. perhaps. With today's basic strategy being pretty much nonexistent then (educated guess), casinos probably didn't have much reason to tighten any rules...people gave the house quite an edge without a consistent playing strategy.

I think that as far as the rules go, things weren't THAT much different from what you'll find at the best single deck games in Northern NV today. I've played in Wendover a number of times and the games are usually dealt pretty deeply, sometimes even to the point of the dealer shuffling up only when there aren't enough cards left to deal another round.

In regard to the rules, they are generally great with the main blemishes being H17 and no DAS.

I think that probably where Thorp was able to gain his biggest advantage was in his ability to spread like a madman. I've seen some of his records from his early trips and he was definitely able to get away with more than 1-4.

One odd thing, though, is that on the "Professor Blackjack" Breaking Vegas episode Thorp himself says that at many points in that initial trip the dealers were NOT dealing deeply into the deck and, as he kept winning, there were times when he was only getting in two hands before they shuffled up on him. So it seems that in many ways the conditions he faced were sometimes NOT better than todays, and in some ways they were in fact worse. And yet he won anyway.

 

[Sonny]

So I am of course familiar with the story of Thorp's Reno/Tahoe trip with Kimmel and supposedly in a period of about 72 hours (and we're presuming this isn't all play time) he more then doubled his bankroll from $10K to $21K.

I thought that Thorp's trip with Manny was to Vegas, not Reno. Wasn't his later trip to Reno with MacDougal? Maybe I'm mixing them up.

-Sonny-

 

[SPX]

I thought that Thorp's trip with Manny was to Vegas, not Reno. Wasn't his later trip to Reno with MacDougal? Maybe I'm mixing them up.

-Sonny-

According to the "Professor Blackjack" Breaking Vegas episode, Manny took Thorp to Reno because he wasn't yet ready to expose him to the Vegas atmosphere. They played in Reno for a couple of days until they essentially had been kicked out of every casino in the town, and at that point they went to Lake Tahoe to continue their exploits.

 

[ChefJJ]

I think that as far as the rules go, things weren't THAT much different from what you'll find at the best single deck games in Northern NV today. I've played in Wendover a number of times and the games are usually dealt pretty deeply, sometimes even to the point of the dealer shuffling up only when there aren't enough cards left to deal another round.

In regard to the rules, they are generally great with the main blemishes being H17 and no DAS.

I think that probably where Thorp was able to gain his biggest advantage was in his ability to spread like a madman. I've seen some of his records from his early trips and he was definitely able to get away with more than 1-4.

One odd thing, though, is that on the "Professor Blackjack" Breaking Vegas episode Thorp himself says that at many points in that initial trip the dealers were NOT dealing deeply into the deck and, as he kept winning, there were times when he was only getting in two hands before they shuffled up on him. So it seems that in many ways the conditions he faced were sometimes NOT better than todays, and in some ways they were in fact worse. And yet he won anyway.

So you would chalk it up more to a great run of positive variance (I still like the term luck :grin: ) rather than favorable conditions? Thanks for the follow up.

good luck

 

[SPX]

So you would chalk it up more to a great run of positive variance (I still like the term luck :grin: ) rather than favorable conditions? Thanks for the follow up.

I would say that it was undoubtedly both. At least initially, I'm sure the conditions he encountered WERE better than anything you're going to find today, though he notes that they deteriorated rapidly as his chip stack grew.

But yeah, I'm sure there was a lot of LUCK involved, especially considering that he not only won, but won BIG.

 

[SPX]

If his overall edge was 2%, doubling a bank doesn't take long with Kelly or half-Kelly bets.

To keep it simple, let's imagine a flat-betting game with a 2% edge, 1.14 var, half-Kelly bets, $10K bank:

Your bet should be (($10K * 0.02) / 1.14) / 2 = $87.72 per hand
Your expected win per hand is $1.75.
Hands to double your bank without bet resizing: 5700
At 60 hands per hour, that's only 95 hours.

Now, I'm NOT saying he had a 2% edge, and this overly simplistic example uses flat-betting. Still, you get the point.

Not being mathematically inclined, would that mean that a flat bettor with a 1/2% overall edge betting Full Kelly would need 190 hours to double his bank?

 

[KenSmith]

No, with a $10K bank and 1/2% edge with 1.14 variance, a full Kelly bet would be $43.86 per hand, which yields a profit of $0.22 per hand. It will take 45,600 hands, or approximately 760 hours to double the bank.

I understand how you got to your question of 190 hours. After all, you've doubled the Kelly ratio, but quartered the edge. Shouldn't the overall effect be a doubling of the hours needed? No. Instead, it takes 8 times as long.

To understand why, let's compare apples to apples, and look at half-kelly vs half-kelly:
Half-kelly with a 2% edge doubles the bank in 95 hours.
Half-kelly with a 0.5% edge doubles the bank in 1520 hours, 16 times as long.
Why? Both the bet size and the edge are 1/4 as much. (1/4) * (1/4) = 1/16 the profit potential.

This gives you some insight into just how powerful it is to find a game with a big edge.

 

[SPX]

No, with a $10K bank and 1/2% edge with 1.14 variance, a full Kelly bet would be $43.86 per hand, which yields a profit of $0.22 per hand. It will take 45,600 hands, or approximately 760 hours to double the bank.

I understand how you got to your question of 190 hours. After all, you've doubled the Kelly ratio, but quartered the edge. Shouldn't the overall effect be a doubling of the hours needed? No. Instead, it takes 8 times as long.

To understand why, let's compare apples to apples, and look at half-kelly vs half-kelly:
Half-kelly with a 2% edge doubles the bank in 95 hours.
Half-kelly with a 0.5% edge doubles the bank in 1520 hours, 16 times as long.
Why? Both the bet size and the edge are 1/4 as much. (1/4) * (1/4) = 1/16 the profit potential.

This gives you some insight into just how powerful it is to find a game with a big edge.

Hmm, that's interesting. Thanks for the response. The math of the game is clearly where I falter.

Let me ask you this real quick. . .

Snyder gives us the formula:

Average Bet x Advantage x Hands Per Hour = Expected Hourly Return

This seems like simple math to me, but ha ha, I never trust my math skills. However, it seems to me that a flat bettor betting $100/hand with a 1/2% edge at 80 hands per hour should yield an expected profit of $40/hr.

Would this be correct or am I off base again?

 

[KenSmith]

However, it seems to me that a flat bettor betting $100/hand with a 1/2% edge at 80 hands per hour should yield an expected profit of $40/hr.

Correct.