Bitcoin Forum

New Site to gamble on!

http://www.infinifire.com/guessthecard/

Currently only supporting guess the suit and for small amounts from .001 to .01
Implemented -
Guess the suit for 4x payout
Send to addresses on page and after 5 confirms it picks it up and pulls a random card if it matches the suit you win.

Planned -
Guess the Face Value(IE 8 or Jack) for x payout
Guess the Exact Card  for x payout

Currently only doing small bets .001 to .01 to make sure there are no issues for a bit.  I sent a few transactions over to it myself to make sure all working but you never know!
ANY Issues PM me or preferred use contact form on the website be sure to mention TX id or whatever you have available to help me track down any issues.

If you have any suggestions feel free to contact me or comment on this thread!

http://www.infinifire.com/guessthecard/

NOW Provably fair see http://www.infinifire.com/guessthecard/about-us/ for details.

Suggestion: Fix the "card drawn" images. They are stretched out.

Is there provably fair?

Had a few people make some bets since post.  Looks like bitcoind is having trouble getting input transaction info for 1 of the 3 so don't bet for now.
the 2 that registered ok 1 of which won!  Grats to whomever you are...hehe

I'm currently not using any fixed number to generate the random card that can be shown for provably fair.  It is just using a rand call to draw the card.  I had thought about shuffling deck and grabing top but would be more prone to repeats and thus less random.  provably fair just means that the number used to generate your outcome is shown to you so you can see how it was gotten is all.

2x payout for 25% chance?

Can you explain a little better?  I'm a developer and not a designer...technically they are shrunk from actual size to fit the page better. This is via the img tag height/width which I kept proportional.

For now yes.  thinking about jacking ti to 3x and also maybe adding jokers in deck for some sorta special bonus win like joker wins your bet back + last 5 bets or something.

To appease the masses that I'm not cheating here I made this provably fair
http://www.infinifire.com/guessthecard/about-us/
Show the details about where to see the seed used and how to calculate the card

NOTE:  These will only show on from now forward guesses as previous guesses were just based on a simple PHP rand which is actually more random then any way that can be provably fair.

You won't get many people playing at those odds. Why play at your site when they can go to some dice or similar site and get close to 4x?

Playing at those odds , no thanks.

Ok,   so looked at dice sites looks like if I did this should match odds to win pretty close:

Add the 2 jokers into deck as loosing cards giving you
13/54 ~ 0.2407% chance to win
with a 4x payout on win.

Basically matching the small house edge of dice best I can with my setup.  Would people play at that?

Oh the site is down for reindex again as I seem to have lost an address in the wallet and with it most the bank :-(  Trying to get them back but doubt I will just a little scared to put much BTC in it right now.

Reindex complete site live with new 4x payout on 13/54 guess the suit.

Hmmm had a few transactions when first announced and now that I make the odds better and it provably fair as asked no one wants to bid?  lol

It's not provably fair. To make it provably fair you need to show information which will allow players to know that the result of the draw can not be influenced by you before they make a deposit.

A possible implementation is the hash of the random seed (possibly add some salt). You will make people even more happy if you use the incoming transaction id as the client seed in addition.

The only way to do what you ask would be to show the cards before hand more or less. 

Even if I hash the random seed with/without salt I would still just be displaying that to user after the fact.  Using the trans ID as the seed might work would need to research a little see exactly where these comes from IE there is no pattern there or the system would basically be exploitable. 

Random is what random is No good way to be random and at same time not have some part hidden.  Else it would be predictable and thus not random anymore. 

Just looked into it and the TX Id is a hash of the TX which in theory could be built in memory and figured before hand thus basically knowing your outcome before it happens so yeah not doing that.

Maybe you should look into what all the dice sites are doing it's basically what I described.

Ok,  now its provable fair as I use my random plus the transaction ID as the seed.  I wont know the transaction ID and you wont know the rand until after so fair to both sides...hehe

just got another player bet .005 won .02 !  congrats

This is NOT provably fair. If I send a transaction now you can select a random seed which makes me lose quite easily. This is bad. You don't need to change it for me but don't claim it's provably fair if it's not. Look into what the others are doing. A solution that works for on-chain games like yours is to have a secret of the day that doesn't change and have the SHA-256 (or whatever) hash of that secret known, the secret should be at least 16 bytes so it's hard to find by brute force searching (feel free to use longer secrets). When calculating the result you combine the secret of the day with the transaction id in same way and then find a card from the deck in some way.

For example you could: card = (HMAC_SHA256(secret,txid)/2^256)/52, the result is an index in a deck of 52 cards (note: this uses big integer arithmetic)

After the day is over you publish the secret. Now everyone can verify that the SHA-256 of the secret (which was known to players beforehand) is the same as calculating SHA-256(secret) when the secret is known.

Yes you can screw up implementing provably fair and leak your bet results beforehand but you can also do it correctly and the game becomes provably fair for everyone.

Ok so I see what your saying since the rand isn't known till after it could be biased which is doubtful but ok. 
So Now you will see sha256 of secret for today posted on home with yesterdays secret(I went with 45 characters don't ask me why that number :-)
so secret+txid though my rand class(posted on about page) will give same card as was drawn during your bid.

That and the fact I've had like 4 bets and 2 won should show me as trustworthy even if it doesn't quite meet provably fair...lol.

I don't get how you think a bitcoin gambling website can succeed without being provably fair. But apparently you don't even understand the concept of provable fairness, so I shouldn't be surprised...  ::)

Maybe a slightly deeper research would have been beneficial to your project?

-erased retort here-

Um pretty sure I've implemented it as said now as my key(seed whatever you wanna call it) is published in hash form and tomorrow will be available in open view for verification and the other part is the tx id which I can't know.  so key+txid = passed to function I published on my site = card drawn for bet.  So nothing is hidden same as your site :-)

Oh and please refrain from negative in no way helping feedback.  I have shown I respond to positive feedback so why even bother doing that?

My message was indeed rather negative only, sorry. I do like your idea, anything different from existing concepts is very valuable. Let's conquer this dice country!

So any new suggestions?

Hmmm the lack of any bids and responses now makes me wonder if I should bother with the guess the card value and guess the exact card modes?  Guess I could look into advertising more...hmmm