The house edge in most dice games is 1%.  It's possible to win in the short term.


That's unlikely.  Just-Dice.com absolutely won't scam you.  It will offer you 1% less than true odds on every roll.  If that's a scam then they scam you, but other than that it's provably fair.

Last night while I was sleeping someone won over 2700 BTC on Just-Dice, taking the house profit from over 2000 BTC to under -700 BTC.  That's a profit for the player of over $250,000 in just a few hours of play.

Now tell me that the site's a scam!  The winning player was able to withdraw his winnings just as soon as I was grabbed them from the secure offline Bitcoin wallet.

That too.  Even if I was dishonest it would make no sense to make a big fuss about "I can't lose" and whatever else he was saying.

I expect you're joking, but I didn't invent provably fair!

The first implementation of it I was was on bitjack21.com (or whatever it was called), and later bitZino.com implemented much the same system.

Before I gave up on a system that was provably fair against the operator cheating, I was thinking of a system where each investor runs a small server of their own which {does something} to each bet in real time, and passes it on to the next investor's server.  Each investor seeds their own server, and so there's no way of cheating unless all the investors cooperate.

But then if any one of them goes offline, the site stops working.

"OK, so any 7 of 10 investors can generate the roll"?

Well, in that case I'll just try various sets of 7 from 10 until I find one that makes me win...

Any way you roll it, I can't see a reliable way of stopping myself from being able to cheat while also having the site be able to process player rolls quickly.

Not really, but the log does contain records of each connection and disconnection.  So if it really mattered, I could go back and work out how many connections were open at any particular point in time.

Going forwards it might be interesting to report that number in real time.

Do I ask these 10 investors for a number for every bet?  10 investors times 20 times per second = a lot of asking!

If not, I can still see what number I'm about to roll, and bet accordingly.

I'm not familiar with everything random.org has to offer.

But is it probably fair?  Is there any way I can prove to the player that the seed that made them lose was fairly chosen by random.org, and not carefully calculated by JD to make them lose?

To be clear, I don't block or return deposits over the 500 BTC.  I just don't credit them to user accounts until I've withdrawn the funds from inputs.io into my real wallet.

This.  Someone won 2700 coins this morning.  And there's no way I can prove it wasn't me.

I woke up at 9am and had to go out straight away.  I had been up until 4am the night before with the site.  I said to Deb that I should check the site before going out.  She said "it was fine 5 hours ago, leave it".  But I logged in anyway, and saw a whole series of 200 BTC bets going through.  Needless to say I was late for my appointment, having had to stay back and go into the cold wallet to cash out the big winner.

I knew that at some point the house would do badly, and was expecting much worse fallout than I've seen so far.  Very few investors have pulled out as a result of the loss, which surprises me to be honest.

Thanks for your ongoing support.  Let's hope the next whale doesn't do quite as well!

That's OK, but the site processes 20 bets per second.  If each bet had to wait for the next football match to finish, we would have a pretty slow site.

No, it is entirely exploitable by me.  At any time I can look to see what my next roll is and bet accordingly.

This is why it took me a year between coming up with the idea for JD and implementing it.  I just couldn't imagine anyone investing when I can just win all their coins.

Eventually, having failed to come up with any even slightly promising workaround for the problem, I decided to just make the site anyway and see what happened.  It seems people trust me enough that they believe I won't cheat them.  I've pointed out this hole in this thread before, I believe.  It's the same issue as at SatoshiDice, where presumably Erik knows the daily secrets and can win at will.

I guess it's just something you have to bear in mind when deciding whether to invest / stay invested.  I could slowly drain your investment by winning against the site.  I could run off with all the invested coins at once.  I won't do either, but I would say that, wouldn't I!

I have over 500 BTC of TF's on hold.  I only accept deposits up to that 500 BTC threshold.  If inputs.io disappears with JD funds, we take the funds from TF's balance.  He's agreed to this to limit JD's CP risk.

* it was over 500 BTC before this morning's losses.  It's probably still over 500 BTC now.

I wish someone would try...

Were you around for while we were testing the site with testnet coins?  I gave lots of players millions of coins to test this out.  None of them succeeded in making a significant dent in the bankroll, and the bankroll increased many times over.  Each time you win a 98% max bet, you win 1% of the bankroll.  Each time you lose one, (about 1 in 50) you double the bankroll.

See where that leads in the long term?

Is the site unclear on this point anywhere?

It says:

"On each bet, each player can profit by up to 1% of the house's bankroll."

(emphasis mine).  Is there anywhere that this needs clarifying.  I don't mean to suggest that the 1% risk is all you'll ever risk.  It is "per roll".

A guy with a lot of coins made a lot of big bets and won.

I just paid him out his massive winnings.

I understand if a lot of people see this as a problem with the site.  I don't.  It's good that we got our first really big whale player.

The hot wallet has seen a lot of activity today, and has been emptied twice.  I need to go out for a while, so it's possible it will be empty again for a while.

Don't panic.  I'll refill it when I'm back.  If you need a withdrawal bigger than 20 BTC I would recommend that you make the request using the web form, put in the address and amount you want, and if it fails, email the support address in the FAQ giving the same details, and I will make the withdrawal manually when I get the email.

It isn't a statistical anomaly.  He has a huge bankroll and thinks that the range from min bet to max bet is too high and allows players to successfully martingale if they have a big enough bankroll.

What do you think about that?  Martingale is a losing strategy, no matter what your limits, in my opinion.

I can't comment on individual transactions, but 10.9k came out of the cold wallet and went somewhere after someone won big.  You can probably work out the rest.

Currently the threshold is 0.005 I believe.  Otherwise correct.

I should put it in the FAQ.

Variance causes profits to rise just as it causes them to fall.  With a positive house edge it causes them to rise with higher probability than that of them falling.

You missed out by not investing.  Profits did increase, to 2001 from 1794.  They may well fall back to 10% less than 1794 at some point.  But they're more likely to hit 2400 than 1600 from here.

I'm sorry about that.  Someone has been attacking the site by continually reconnecting to it.  If you connect over and over it will temporarily block your IP address.  Like you say, using a device with a different IP address will fix the problem, as will waiting for the block to expire.

Or just contact me using the email address in the 'contact' section of the FAQ and I can manually unblock your IP address.

JD does log IP addresses and chat conversations.  None of this information will be shared with any third party unless I'm compelled to by law.  It's useful to have this information when investigating past events.