Just-Dice.com : now with added CLAMs : Play or Invest

[mechs]

If we made max profit only 0.2% it would be 50BTC now and still better than almost all the competition.

[dooglus]

If we made max profit only 0.2% it would be 50BTC now and still better than almost all the competition.

In the first few weeks the site was winning, and lots of investors were asking for "more than 1% risk!".  Now the site's losing, and investors want "less than 1% risk!".

I can see I'm going to have to implement investor-settable risk factors one way or the other.

I won't change the default from 1%, since that's what everyone signed up for, but I will allow you to change your own individual risk factors as you like.  It's going to take time to implement and test however.

In the mean time, if you're uncomfortable with the 1% risk, I would recommend divesting.

[iANDROID]

If we made max profit only 0.2% it would be 50BTC now and still better than almost all the competition.

In the first few weeks the site was winning, and lots of investors were asking for "more than 1% risk!".  Now the site's losing, and investors want "less than 1% risk!".

I can see I'm going to have to implement investor-settable risk factors one way or the other.

I won't change the default from 1%, since that's what everyone signed up for, but I will allow you to change your own individual risk factors as you like.  It's going to take time to implement and test however.

In the mean time, if you're uncomfortable with the 1% risk, I would recommend divesting.

Investing money( or BTC) is a form of gambling for me, just let it this way.

[MRKLYE]

Has the site been hacked?

I try and connect to the site and all it says is "No."

Or did the generator run out of gas..?

Police raids? Yeti attack?

Site down for anyone else?

</freakout>

[dooglus]

Has the site been hacked?

I try and connect to the site and all it says is "No."

Or did the generator run out of gas..?

Police raids? Yeti attack?

Site down for anyone else?

</freakout>

The site blocks you if you try to connect too often or chat too fast.  It's an attempt to prevent the spambots and floodbots we've been seeing.  Sorry you got caught in the crossfire.  I'll unblock you now.

In general, if you go get blocked, the block only lasts for an hour.  But that can be annoying, I realise.

[stripykitteh]

Just-Dice would have to be the ultimate 'hands-off' investment. If you trust dooglus, just invest whatever you feel comfortable with, and wait for the law of large numbers to do its work.

The thing is, if your investment horizon is measured in hours or days, you will often be disappointed.

Dooglus, I take it you are familiar with the Kelly Criterion for investing? It looks like Just-Dice is using a half-Kelly, would you agree with that? A half-Kelly is a reasonably conservative approach; I wouldn't want to make it more conservative than that.

[Mooshire]

It's sad that there have been so many fake accounts.

[dooglus]

Dooglus, I take it you are familiar with the Kelly Criterion for investing? It looks like Just-Dice is using a half-Kelly, would you agree with that? A half-Kelly is a reasonably conservative approach; I wouldn't want to make it more conservative than that.

I'm not especially familiar with it.  Can you tell me more about this "half-Kelly"?

I arrived at the 1% risk being optimal mostly by simulation.

[stripykitteh]

Dooglus, I take it you are familiar with the Kelly Criterion for investing? It looks like Just-Dice is using a half-Kelly, would you agree with that? A half-Kelly is a reasonably conservative approach; I wouldn't want to make it more conservative than that.

I'm not especially familiar with it.  Can you tell me more about this "half-Kelly"?

I arrived at the 1% risk being optimal mostly by simulation.

It's basically working out the optimal amount to invest when you have a known edge, and many trials.

Try this:

http://www.investopedia.com/articles/trading/04/091504.asp

(The wikipedia article is more comprehensive but a bit harder to understand, for me at least.)

It's simply stated as:

Kelly % = W – [(1 – W) / R]

Where:
W = Winning probability
R = Win/loss ratio

So if W = 0.505, R should be 101:99 ~= 1.02, and plugging the numbers in we get:

Kelly % = 0.505 – [(1 – 0.505) / 1.02] ~= 0.0197

i.e., the optimal amount to risk is about 2% of the bankroll. You are at 1%, or a half-Kelly. You are trading some growth for less volatility.

If someone thinks I've got this wrong I welcome the correction.

[vandinn]

If we made max profit only 0.2% it would be 50BTC now and still better than almost all the competition.

In the first few weeks the site was winning, and lots of investors were asking for "more than 1% risk!".  Now the site's losing, and investors want "less than 1% risk!".

I can see I'm going to have to implement investor-settable risk factors one way or the other.

I won't change the default from 1%, since that's what everyone signed up for, but I will allow you to change your own individual risk factors as you like.  It's going to take time to implement and test however.

In the mean time, if you're uncomfortable with the 1% risk, I would recommend divesting.

That would be an amazing feature, although judging from the comments on this forum most investors will be unable to estimate their short term risk from variance... I feel bad for you for having to face all the crap that people say here. You did an absolutely fantastic job here. I believe this may once become the biggest online casino in the world (if it isn't close to that already). Superb job.

[MRKLYE]

Has the site been hacked?

I try and connect to the site and all it says is "No."

Or did the generator run out of gas..?

Police raids? Yeti attack?

Site down for anyone else?

</freakout>

The site blocks you if you try to connect too often or chat too fast.  It's an attempt to prevent the spambots and floodbots we've been seeing.  Sorry you got caught in the crossfire.  I'll unblock you now.

In general, if you go get blocked, the block only lasts for an hour.  But that can be annoying, I realise.

Thanks Doog. I got my roommate into BTC and showed him your site today. Mind crediting user 33383 a bitcent if you are still running that promo?

Thanks again for unblocking. I feared the site had been defaced!

[stripykitteh]

A bit more on the half-Kelly bet:

http://thehackensack.blogspot.com.au/2009/11/half-kelly-bet.html

The thing that surprises a lot of people is that you can go backwards significantly even when the odds are in your favour and your strategy is perfect.

For me, if I wanted to be sure my investment never went backwards I'd buy government bonds. A little bit of risk for a high return sounds like a sweet deal.

[dooglus]

Thanks again for unblocking. I feared the site had been defaced!

I've made the message more sensible that just "No." now.  I was thinking (stupidly) that only the attacker would ever see it.  It'll change next time I restart the server, but people were betting quite actively when I went to restart it and I didn't want to disturb them.

Edit: I should warn you, that if you and your roommate are on the same IP address with different accounts, the spam filter will get upset if you both talk around the same time.  The spammer uses a single IP address to control multiple accounts, so I used that as one of the ways of detecting spamming.

[dooglus]

Kelly % = W – [(1 – W) / R]

Where:
W = Winning probability
R = Win/loss ratio

So if W = 0.505, R should be 101:99 ~= 1.02, and plugging the numbers in we get:

Kelly % = 0.505 – [(1 – 0.505) / 1.02] ~= 0.0197

i.e., the optimal amount to risk is about 2% of the bankroll. You are at 1%, or a half-Kelly. You are trading some growth for less volatility.

If someone thinks I've got this wrong I welcome the correction.

I think you've got this wrong...

You have to look at it from the house point of view.

Consider the 49.5% game.  The house has a 50.5% chance of winning, or W = 0.505.

R is the amount the house wins when it wins (1 unit) divided by the amount it loses when it loses (1 unit), so R = 1/1 = 1

Kelly = W - (1-W)/R = 0.505 - (1 - 0.505)/1 = 0.505 - 0.495 = 0.01 = 1%.

Notice it's the same for all bets (funny that - evidence for intelligent design??):

>>> w = 0.02 (98% game)
>>> r = 1 / 0.01020408
>>> w - (1-w)/r
0.01

>>> w = 0.25 (75% game)
>>> r = 1 / 0.32
>>> w - (1-w)/r
0.01

>>> w = 0.5 (50% game)
>>> r = 1/0.98
>>> w - (1-w)/r
0.01

>>> w = 0.505 (49.5% game)
>>> r = 1/1
>>> w - (1-w)/r
0.01

>>> w = 0.75 (25% game)
>>> r = 1 / 2.96
>>> w - (1-w)/r
0.01

>>> w = 0.999999 (0.0001% game)
>>> r = 1 / 989999.0
>>> w - (1-w)/r
0.01

More generally, payout * chance = 1 - edge, (1)
W = house_chance = 1 - chance (2)
R = 1 / (payout-1) (3)

Kelly = W - (1-W)/R
= (1 - chance) - chance*(payout-1) (using 2 and 3)
= 1 - chance - payout*chance + chance (expanding)
= 1 - payout*chance (cancel chance)
= edge (using 1)

So the Kelly factor is the same as the house edge, whatever the edge.

I never worked that out like that before, but it's a nice result.

[stripykitteh]

D'oh, thanks for the correction. Yeah, the reward/penalty for win/loss matters.

So the site is actually configured for the most efficient growth with a 1% edge; accepting that the results can be volatile.

[KingOfSports]

To any who complain over the 1% house edge or not seeing results, you have to understand this is an INVESTMENT opportunity. Not ALL investments make money. In the long run THIS SHOULD make 1% on average of all bets, but that is NOT guaranteed. Complaining about this after the site went from +2000 to -1000 should be a sign that this investment might not be for you and in which I would advise you to divest.

[nimda]

Next question:

When the socket returns a "result," what is the value of stats.luck supposed to represent?

[dooglus]

Next question:

When the socket returns a "result," what is the value of stats.luck supposed to represent?

It's the overall luck of all players, which is number of bets they've won as a fraction of the number they are expected to have won, given the chances they've been playing at, multiplied by the number of bets that have been placed.  If you divide it by the total number of bets placed and multiply by 100, you get the site luck as displayed on the page.

Ugly, I know, but it serves you right for peeking! 

[Mooshire]

The bankroll of this site scares me.

EDIT: Dynamic image with the site's bankroll. Maybe add to OP?

[dooglus]

The big player is back again, if anyone's interested: