BR Collapsed 50%, What To Do!?

[nc-tom]

That is assuming his goal is to win 100 units. His risk of going broke before winning 100 units is probably about 35%. If you look at the lifetime RoR (with no goal or time constraints) it will probably be closer to 75%. That gives him a 25% chance of not going broke if he continues to play at that level.

-Sonny-

Well again using the simple function on cvcx, with a 100 un bankroll, win rate per 100 hands at 2.15, std dev per 100 hands at 27.79 the ror is 57.24%.

 

[Sonny]

Well again using the simple function on cvcx, with a 100 un bankroll, win rate per 100 hands at 2.15, std dev per 100 hands at 27.79 the ror is 57.24%.

A win rate of 2.15 units using a 1-5 spread? I guess it depends on the penetration, but that sounds way too high to me. I assumed a 1 unit win rate with a 27 unit SD. We would need more details about the game to give an accurate ROR, but I would think that anything even remotely close to 50% would be wildly unacceptable for most players. In that sense it really doesn't matter what the precise numbers are. This guy has been overbetting his BR from the beginning and has worse than a 50/50 shot at success if he continues to play this way. The odds are against him.

-Sonny-

 

[Automatic Monkey]

Yes, and not only is that underfunded, 1-5 is a pretty weak spread for DD, as DD is generally dealt today. Sounds like he'd be better off stretching the low end of the spread to 1-8 or 1-10 and Wonging shoes instead.

 

[zengrifter]

I recevied this privately, for Moo from MMMM. zg

Quote:
Originally Posted by moo321
You can't be more likely to lose than win if you're playing with an edge, at least not at the 100 unit level or higher. Your risk of ruin might be 25 or 30%, but not above 50.

Is Moo right? Anyone? zg
__________________

Of course MOO is not right. You can have over a 50% chance of going broke even while playing with the edge.

One example is right here. You get one bet and one bet only. A person is offering you 10 to 1 odds if you can predict the roll of one 6-sided die. You have well over 50% chance of losing, 5/6, but you are certainly playing with an advantage.

A lot of people (like Moo) think that just because you have an edge you are a favorite to win. Not true.

Another good example is betting 2X kelly. You have the edge (assuming AP playing blackjack) but you have a 100% ROR in the longrun.

 

[moo321]

There's no way you can have more than 50% risk of ruin with an advantage. If you do, you're not playing with an advantage. I'm assuming youre only talking about doubling the bank. If your target is higher, then that changes everything.

 

[zengrifter]

There's no way you can have more than 50% risk of ruin with an advantage. If you do, you're not playing with an advantage. I'm assuming youre only talking about doubling the bank. If your target is higher, then that changes everything.

I think that you are mistaken, but being a NEOPHYTE I'll defer to any expert who will dispute this. zg

 

[jack.jackson]

I think that you are mistaken, but being a NEOPHYTE I'll defer to any expert who will dispute this. zg

A good poker player knows. He who has the biggest BR has the advantage.
Thats because he can ride out longer losing streaks opposed to a person that has less of a BR.
The same law applies here. Even if you were to play in positive shoes only with an advantage. That fluctuation will bounce back and forth so violently in the begining. It is therefore more likely that if you only have 20 max bets to play with. Your true advantage will never have a chance to assert itself, because variation will swing back and forth. Im not saying you'll always lose because you wont. But unless you have a substanial BR to back you up. Variation will snuff you out before you ever get a chance to win it back. This is were the theory of gamblers ruin shows its importance.

I thought id take a stab at it. Maybe somebody can explain better than i can.

 

[Automatic Monkey]

I think that you are mistaken, but being a NEOPHYTE I'll defer to any expert who will dispute this. zg

Yes, your RoR can be greater than 50% with an advantage. If this were impossible, it would be impossible for ploppies who always play with a disadvantage to win, and we see them win all the time, sometimes a lot more than we do.

To take it to the extreme, let's say I walk into a casino with $500, backcount until I have a 2% advantage, then bet the $500 on one hand. Even with a 2% advantage you will still lose more hands than you will win. You will probably lose that $500.

To be less extreme, there are always fluctuations and we don't know exactly what the advantage is going to be of any series of hands. The RoR is the chance of a series of losing hands coming along faster than your bankroll is being built up by your wins.

 

[moo321]

I'm assuming that your target is to double your initial bank. And if that's the case, and you're not betting something ridiculously large (like 1 max bet for the whole bank) then there simply can't be any way the risk of ruin is even 50%, by definition. Thats how you define an advantage; it means you're more likely to win than to lose.

There's no way that, playing with an edge, you can be more likely to lose all of your money than double (unless your playing with so few units that the slightly non-linear nature of blackjack comes into play). If we were playing video poker, then I would agree that your risk of ruin could be above 50%, because your advantage comes from hitting royals every few thousand hands.

 

[zengrifter]

There's no way that, playing with an edge, you can be more likely to lose all of your money than double (unless your playing with so few units that the slightly non-linear nature of blackjack comes into play). If we were playing video poker, then I would agree that your risk of ruin could be above 50%, because your advantage comes from hitting royals every few thousand hands.

Yes, too few units - 100u with 5u max bet and insufficient spread to boot. zg

 

[Sonny]

I'm assuming that your target is to double your initial bank. And if that's the case, and you're not betting something ridiculously large (like 1 max bet for the whole bank) then there simply can't be any way the risk of ruin is even 50%, by definition.

If you are betting double-Kelly or higher then your ROR is 100% even if you have an advantage. If you have a 1% advantage and you always bet 2% of your bankroll then you will eventually go broke, no question. It may happen after you have doubled your bankroll (maybe even a few times) but it will happen if you play long enough.

Similarly, if you never reinvest your winnings back into your bankroll then your ROR is 100% (theoretically).

Thats how you define an advantage; it means you're more likely to win than to lose.

No, your advantage is defined by how much money you expect to win, not by how likely you are to win it. For example, think about a game based on the result of one fair die. If you roll a 6 then you win $10. Any other number causes you to lose $1. Obviously you have a very healthy advantage even though you are always more likely to lose the next game.

The same is true in BJ. We get an advantage because of blackjacks and double downs, not because we are more likely to win the hand (we are pretty much always the underdog, even in positive counts).

Just because a player has the advantage in the short-term doesn’t mean that he cannot lose in the long term. That is why proper bankroll management is so important in this game.

-Sonny-

 

[Dyepaintball12]

Now, I'll admit that i do not know that much about Bankroll, but from what I have read you need to keep adjusting your BR to optimize your return by increasing your bet sizes.

Now, wouldnt that go the other way as well, so every time you lose part of your BR, you need to lower your bets so you are not overbetting?

So, wouldnt losing half of your BR mean you need to start betting half of what you were currently betting?

(I mean in general, not this case b/c it seems he was severly over betting)

 

[Sonny]

So, wouldnt losing half of your BR mean you need to start betting half of what you were currently betting?

Yes, although it depends on how lucky you feel. =)

When you first develop your bet spread you will have a certain ROR associated with it. For example, if you size your bets to full Kelly and never resize them then you will start with a 13.5% ROR. But, if you know that you are going to cut back if/when you lose half of your bankroll then your initial ROR is only about 5% from the start.

Most ROR formulas assume that you will continue to use the same bets forever. In reality this doesn’t happen. As you mentioned, most players raise their stakes as their bankroll increases and lower their bets if their bankroll dwindles. Resizing your bets to fit your bankroll is the foundation of Kelly betting. As your bankroll increases, so does your profit. When your bankroll decreases, so does your risk. You are maximizing your profit while minimizing your risk.

Although resizing your bets is not mandatory, it is a very good idea.

-Sonny-

 

[Automatic Monkey]

I'm assuming that your target is to double your initial bank. And if that's the case, and you're not betting something ridiculously large (like 1 max bet for the whole bank) then there simply can't be any way the risk of ruin is even 50%, by definition. Thats how you define an advantage; it means you're more likely to win than to lose.

There's no way that, playing with an edge, you can be more likely to lose all of your money than double (unless your playing with so few units that the slightly non-linear nature of blackjack comes into play). If we were playing video poker, then I would agree that your risk of ruin could be above 50%, because your advantage comes from hitting royals every few thousand hands.

Your illustration with the royal is a good one because it demonstrates the effect of variance on bankroll and ruin, but it is easier than you think to have a larger than 50% RoR.

Suppose you have a biased coin that comes up heads 51% of the time. You have an advantage on every flip (assuming you bet heads) but if you are betting 10% of your BR, the chances are quite high that you will lose it all. I'm getting something around 80% RoR without doing much math. This is the ubiquitous Gambler's Ruin Paradox. It's all based on the fact that once you run out of money, they won't let you play anymore. There will be winners and losers in a coin-flip game as described, and even though the winners will win more than the losers lose, most players still will lose. The situation is worse in BJ because all of our profit comes not from something as extreme as royal flushes, but from naturals which hit once every 21 hands.

 

[moo321]

I think we're arguing about different situations. I'm ONLY talking about your risk of ruin versus chance of doubling the bank, and even with 100 units it's probably less than 50%. But, if we're talking lifetime risk of ruin, then certainly it can be higher than 50%.

 

[Sonny]

I think we're arguing about different situations. I'm ONLY talking about your risk of ruin versus chance of doubling the bank, and even with 100 units it's probably less than 50%. But, if we're talking lifetime risk of ruin, then certainly it can be higher than 50%.

Yeah, I think you're right.

-Sonny-

 

[jack.jackson]

I think we're arguing about different situations. I'm ONLY talking about your risk of ruin versus chance of doubling the bank, and even with 100 units it's probably less than 50%. But, if we're talking lifetime risk of ruin, then certainly it can be higher than 50%.

I dont see it as arguing. But rather discussing. As matter of fact, If it wasnt for you. I dont think we would've gotten anywhere with is. We actually need people to ask "why". Its what makes the world turn. Good work

 

[Automatic Monkey]

I think we're arguing about different situations. I'm ONLY talking about your risk of ruin versus chance of doubling the bank, and even with 100 units it's probably less than 50%. But, if we're talking lifetime risk of ruin, then certainly it can be higher than 50%.

Well sure, if you have a really small bank, it's easy to double as well as lose.

But you can double it first and then lose it, too.

 

[zengrifter]

OK, so we're in agreement that grossly overbetting will NOT result in greater than 50% RoR IF the target is simply to double the bank?

This is counter-intuitive (no pun intended) because I can think of another example -

What if I have 1000u and I bet 4xKelly - can my RoR be only 50% if my target is to double my bank?
​

Thats where it falls apart for me. zg

 

[moo321]

Yeah, so long as it's not like 5 max bets total. Then the non-linearity of blackjack could come into play.