We had a guy playing pretty heavily for an hour yesterday, but he got nowhere near nakowa levels.

Here's how his play affected the site's expected profit:



ie. in one hour the expected profit went up 40 30 BTC, so he wagered around 4000 3000 BTC.  That's 1000 BTC every 15 20 minutes, or about 15 20 times slower than nakowa.

Edit: here's how it affected the actual profit over the same time period:



Edit2: 105 - 75 = 30, not 40!

Don't soldering iron me bro!

I think the simplest explanation is that there are a limited number of people who:

a) have a lot of Bitcoins
b) are willing to risk them on a gambling site
c) know about Just-Dice

Most of those people already lost their coins.

In the early days we had a number of people who came to the site to bankroll it and who ended up gambling instead. It's a kind of natural selection that the people who held on to their coins are the people who are able to resist that temptation; the strongest survived and are less willing to take risks with their share of the bankroll.

We still get some who do it, but less than we used to.

That sounds very unlikely.  With a max bet of 500 BTC that's 2 bets per second for 24 hours.

I don't think he was playing that long, or that fast, or that large.

>>> 1553357.82296363 / 24 / 60 / 60
17.978678506523497

That's 18 BTC per second, which while still crazy sounds more plausible.

Edit: maybe you meant $1000 per second?

Yes, go to JD, click on 'stats' and then 'wagered per day'. 

If the subject is anything like "double your Bitcoin in 4 business days" then it's safe to stop reading since it's obviously a scam.

Seals is a 4.5 and would be a 5 if the software was better.

Maybe one day they will release the source of their Linux client so I can try it.

This looks like a scam.

There's a 2 hour gap after he asked for the coins to be sent back to him in which I did so and then he put them back into the gambling account again.

He moved the coins around a few times I think.

Yes.  You need to consider how much the house should risk, considering the odds the house is getting.

That is different than considering how much the player should risk, considering their odds.

It's not symmetrical, which is somewhat counter-intuitive.

What if it lasts 4 hours without pills?

... or colour it in and add a penis...

24 hours results don't really tell you much.

Here's how the site did over the last couple of days:



It's very up and down.

To get a real idea of how things are going, you need to zoom out a lot.

Did you see this log I made of his chat and his bets?

http://pastie.org/pastes/9252179/text

f = (bp - q) / b

where f is the fraction to risk,
b is the payout multiplier minus 1
p is the probability of the house winning
q is the probability of the house losing

So in the 49.5% bet, where the payout is 2x,
b = 2-1 = 1
p = 0.505
q = 0.495
f = (1*0.505 - 0.495) / 1 = 0.505 - 0.495 = 0.01 = 1%

And in the 33% bet, where the payout (for the house) is 1.5x,
b = 1.5-1 = 0.5
p = 0.67
q = 0.33
f = (0.5*0.67 - 0.33) / 0.5 = (0.335 - 0.33) * 2 = 0.01 = 1%

And it's the same for every other bet:

If the player has probability q of winning, the payout to the player is 0.99/q
When the player risks 1 unit, the house risks 0.99/q - 1 unit
That's a payout multiplier for the house of 1 / (0.99/q - 1) + 1

b = 1 / (0.99/q - 1) + 1 - 1
f = (b*p - q) / b
  = (p/(0.99/q - 1) - q) * (0.99/q - 1)
  = (p*q/(0.99 - q) - q) * (0.99 - q)/q
  = (p/(p - 0.01) - 1) * (p - 0.01)
  = p - (p - 0.01)
  = 0.01
  = 1%

I'm pretty sure it applies for all odds.  You need to look at the payout that the house is getting.  When a player risks 1 unit at 33% for a 3x payout for example, the house is risking 2 units for a 1.5x payout with a 67% chance of winning. If you apply the Kelly Criterion on those numbers you'll see that it's still optimal to risk 1% of the bank.  And the same applies no matter what odds the player is getting.


I don't think it does.  It changes for the player, but not for the house.  Of course the player has a negative expectation and so shouldn't be playing anyway.

He's referring to the Kelly criterion which tells you the optimal amount to risk when you have a positive expectation.

It turns out that Kelly recommends you risk the same amount of your bankroll as the house edge percentage.  Since JD has a 1% house edge, "full Kelly" means 1%.

There's a tradeoff to be made between volatility and expected profit.  We're conservative in only risking 0.5%.

This article is a good introduction to the concept, and includes this image which shows how volatility and profit trade off against each other:



See this, too:

http://compoundingmyinterests.com/compounding-the-blog/2012/10/12/how-did-ed-thorp-win-in-blackjack-and-the-stock-market.html

It's not clear what he was trying to do, but 7000 wasn't his goal, since he reached that and kept playing.

While he was playing I got the impression that he had resolved to play until he lost. I think he said several times for investors not to worry about his wins because they would get their coins back in the end, or words to that effect.

I see JD as a platform I provide where anyone who wants to can provide the bankroll, or the action.

If you provide a lot of the bankroll, you stand to profit from advertising the platform to people who will provide the action.

I'm happy to let things play out and see what happens.

If people stop playing so profits stagnate and the bankroll gets divested, that's fine with me too.

Use it however you see fit, and I'll keep it up and running, and look after the coins.

If enough people do that, they can afford to run for quite a while: