http://blockexplorer.com/tx/5bdd18a15db46269301c02782dd2ec0e7dee126ef2d93ea0fec28da0734ce940#o0 shows you received the full amount.  It's in the same block as your bet.

See also:

I had a run of losses, and now my balance has gone all scientific notation:

Agreed.  A "new address" button gives the best of both worlds.

It's kind of traditional to use a different bitcoin address for each transaction.  I've deposited twice and been given the same address to deposit to both times.

I don't care, personally, but maybe some clients would.

I hit control-R.  Whatever. 

Another observation:

When the dealer's playing, the slow reveal of the hole card takes longer than his next 3 or 4 cards.  So for a while I can see his 1st, 3rd, and 4rd card before I can see the 2nd card.  Which is just a bit weird.

And don't forget that timing me out because I've been sat half-way through a hand for 15-minutes should log me out, but leave me in the same place when I log back in.  


Sometimes when I reload a page that made a POST request, it re-makes the POST request.  Is it only when the POST times out that the reload does a GET?

Yes - I think a simple colon after each of the 5 result words would be better.

Win: +2
Blackjack: +3
etc.

Probably a silly point, but "lose -2" reads strangely.  If I lose -2, don't I win +2?

Funnily enough, my Internet just went down.  While it was down, I clicked 'buy in', and eventually got an error page from Chromium.  When the connection came back, I refreshed the page, and got:


The browser's address bar is now showing https://bitzino.com/table_transfer rather than the usual address, but I didn't change it.

(So I guess that answers my question!)

Thanks for the bitcoin. 

I was wondering about timeouts too.  My Internet connection is pretty flaky here.  What happens if it goes down for an hour part way through a hand?  Can I expect the hand to continue when I get back online?  What if I click 'hit', but the connection is down at the time?  Will the client deal nicely with not getting a server response and let me try again later?

I guess ideally I'd like to be able to have my browser crash part-way through a hand, then log in on a different computer and see the half-finished hand still in play.  But maybe that's expecting too much.

I just noticed that whatever the currency unit I set, the withdraw screen is in whole bitcoins.  It might make more sense to use the preferred base unit there too (and anywhere else that you show currency values - like in the history of deposits).

Wow.  You really are open to feedback aren't you!

I don't know if you're aware of how big the swings can be in blackjack.  Offering a 10 BTC max bet exposes you to the possibility of some pretty big losses if someone plays the max bet and has a good run.  Maybe you've considered that and are prepared to lose a lot, but I thought I should mention it.  There's probably a reason the other sites offer less than half that as their max bet.


Oh, I see.  The shuffle is applying a permutation to the pre-existing shuffle.  The client gets to decide the permutation, but doesn't have any way of knowing the original state, and so can't control the final state.

I made a small deposit last night, played a few hands, and withdrew - mostly just to check out how it worked.

It all went pretty smoothly, but I had the following comments:

* it seems you wait for 7 confirmations before marking my deposit as 'confirmed'?  that seems like a lot, but since you allow me to play unconfirmed balances it's not a problem

* if I had been able to 'cancel' my withdrawal request, I would have, and would have played more hands.  Is there any reason you wouldn't allow players to cancel a pending withdrawal request?

Finally, I just noticed a small issue:  if I click my name in the top right, select a new 'base currency', click 'update', then click 'back', then the "Welcome to Blackjack!" box in the centre of the page still shows my balance in the old currency units.  So if I was in mBTC before, but have less than 1 mBTC left, so I switch to uBTC, I still can't buy in because the buy-in box is still prompting for the number of mBTC to buy-in with.

If I click 'leave' in the top right then the currency units update, but that's a workaround I shouldn't have to use.

Are you aware that bitjack21 has only a 0.45% edge (they stand on soft 17), and strike sapphire's is only 0.50% (only 6 decks, let you hit split aces, but only split to 2 hands)?

I don't know about the other bitcoin blackjack offerings, but both of these have more attractive offerings than bitzino.


Well, the input does affect the output...  but like I said, the 2nd shuffle is entirely for the user's protection, not the site's.


The thing is, there are about 10^672 (2^2229) shuffles of 8 decks, but only about 10^78 (2^256) different sha256 hashes.  So each secret hash corresponds to about 10^594 (2^1973) different shuffles.

A rainbow table won't help.  Each time I see the same secret (which happens about once every lifetime-of-the-universe), it will correspond to a different shuffle.

ie. you really don't need salt in this case, and so can simplify the verification process.

The words "your" and "deposit" overlap, as seen in this screenshot:



It's probably got to be a browser bug, since the HTML looks fine.

I'm using Chromium 18.0.1025.151 (Developer Build 130497 Linux) Ubuntu 12.04.

Isn't that always a push?


According to http://wizardofodds.com/games/blackjack/calculator/ it's around 0.66%.

8 decks
hit soft 17
double after split
double any 2 cards
resplit to 4 hands
can't resplit aces (right?)
can't hit split aces
only lose original bet to dealer BJ
no surrender
blackjack pays 3:2

I don't think this is necessary at all.  The Mersenne Twister bit is for the user's safety, not yours.  You've already securely shuffled the deck, and are just letting the user "cut" it.  Any vulnerability would be equivalent to the player being able to always cut to exactly the 29th card in the deck.  It allows him to cut predictably, but doesn't help him win in any way at all since he has no way of knowing the order of the uncut deck.

So there's no need for you to provide your own 'server_seed' - just use the client_seed for the 2nd shuffle.

Great that you're using a provably fair shuffle.

I found a typo:


"Let's reshuffle the deck using the the Fisher-yates shuffle algorithm"

Here are updated stats, along with a graph showing profit over time, along with expected profits given 1.0% and 1.5% house edges.

Can you clear something up for me?  If I bet 2 BTC on Teh Beast, do I get (a) the currently advertised odds (b) the odds recalculated as if my 2 BTC was already in the pot or (c) different odds for my two spins?

It looks to me like it's (b), which means I'm better off sending two separate 1 BTC bets in 2 different blocks - because that way my first bet gets better odds.  Is that right?


Your job seems to have cleaned up most of the old pending bets.  What's going on with this one?

03a804d79a24ea92112c968652474911666ee57a5b67b10cd265c2d5c2393843

Its 3rd output (output 2, counting from zero) is unspent, whereas all the rest are spent.  That's the oldest pending standard transaction now - and it's only 2 days old.