Topic: BTCRabbit - BiTCoin Lottery (Read 1258 times)

Actually, it's quite possible. Check: https://www.pevpot.com/provably-fair  for a concrete example  


(PevPot never knows how many tickets will be sold, but has no problems being provably fair. There's a few different ways to do this too, I believe)

Enhu, thank you for the recommendation. We checked Random.org and unfortunately it does not help for being provably fair.

But we can let Random.org to pick the numbers as you mentioned. Free API is too limited to use such a service, but we have to decide if it worths to make serious payments for a third party random number generator.

Also a provably fair version of BTCRabbit (with fixed number of tickets of course) is on the way. Which is less profitable for players since the chance of winning will decrease as we explained in our previous post but it's up to player's choice    

Can't you just use random instead. maybe edit the script to simply execute how many tickets were sold before the scheduled hour of the draw, a sequence is then counted and use the random.org to generate who wins. I believe some scripts already exist and it think this could prove provability.

That's a lot to read to find out all your saying is there is no "PROVABLY FAIR"

Hi there,

Thank you all for the feedback.

We've added number of tickets sold for that particular date to home screen (just above the last transactions table). Jackpot is constant until 200 tickets are sold, after that it increases accordingly. It is constant under 200 tickets because otherwise the jackpot becomes too small, and we do not want to give small prizes

The "provably fair" is quite tricky though. It is because the definition of the provably fair.

To make a system provably fair, which means results will be known before the game played (dice rolled, ruffle made etc), is impossible for a ticket based lottery system, unless you know how many tickets will be sold (or how many tickets will attend to lottery).

To make it more clear, let's give an example. Suppose that you pick a number between 0-99 and a random number has chosen between 0-99, and you win or lose. You can make this provably fair because you know that there are 100 different possibilities on every game (0, 1, 2, 3, ....., 99).

Another example, suppose that there is a bingo game, you won or lose according to 6 balls chosen out of 46 balls. Again, you guarantee that there are 46 different possibilities on every pick (1, 2, 3, 4, ....., 46). So you can make it provably fair because you know that on every game there is a constant number of possibilities.

If we come back to BTCRabbit, it is a bit different. We cannot know how many tickets will attend the lottery before 23:59:59 that particular day. So it is impossible to know the result in the beginning of the day. Because there is no constant number of possibilities.

We can set the number of tickets available for that day constant. Let's say there will be 500 tickets will be available for tomorrow. So we can make it provably fair, because we know that there will be only 500 possibilities. However, if players purchase 300 tickets out of those 500 tickets, then prizes might go to unsold tickets. And also this decreases the winning chance of players.

Let me tell this with an example as well.

Scenario 1: Number of available tickets is not constant. For that day 300 tickets sold to 300 different players. So every player has 1/300 chance of winning. In this scenario, you can not make it provably fair because you cannot know how many tickets will attend to lottery in the beginning of the day.

Scenario 2: Number of available tickets is constant and been set to 500. For that day, 300 tickets out of 500 sold to 300 different players. So although number of players is same as the scenario 1, now every player has 1/500 chance of winning. But we can make this scenario provably fair, since we know that, sold or not sold, there will be 500 tickets attending to lottery.

As BTCRabbit Team, we picked the scenario 1 system because we want to increase the winning chance of every player. We have quite bunch of coin based web sites (you can see on my signature) and we are always trying to be fair and user friendly with high quality standards. Now we are considering to launch another lottery game, which is provably fair, but with less chance of winning. So players can pick the game according to their preference

Congrats on your new project Aliser. Site looks solid. I didn't play last year but I'll try my luck this time when I fix my wallet.

I bought some tickets but I didn't even get paying off. Tonight I'll try again but if I won't get anything I lose hope about this lottery. Maybe new year special lottery would be better with bigger prizes.

A New useful project by you, Aliser. This forum needs such an innovator determined person. People in Turkish side should take advantage of your knowledge. I will instatly try New system. Good luck on your projects.

OP I think everybody wants to know the provability of the website.They're waiting for the answers.Excuse me if I'm wrong but you're online on the forum and we're expecting a reply .

It might be interresting to give it a try ! Yet there's already lot of bitcoin lottery...

And for this kind of sites beeing provably fair is nowaday mandatory...

Yet another Bitcoin lottery. There is already a lot of Bitcoin lottery sites out there. In order to stand out from others you will need to have unique features. Do you have any unique features? If so, what is it?

Also, as others mentioned, how do the system select a winning ticket? Will user be able to validate that the winning ticket is the correct one - provably fair? I visited your site and overall it is designed well but lack of some big features.

I did not see anything about this site being provably fair? Did i miss it? How to you pick the winner?

Is it possible to see number of tickets sold? i've visited you site i only see the jackpot prizes, winners and last transactions.

How are you choosing the winner? Using the random generator online? Any measures for us to confirm the lottery is probably fair?

Best of luck amacar2

Please tell us about the result.

Thank you very much dukeneptun. Yes this is obviously a relaunch.

BTCRabbit is working exactly as you asked, there is a default jackpot. And jackpot increases after participation reaches to a threshold.

I have deposited some to grow jackpot money a little bit. Hope to get 1st prize however i am quite unlucky interms of lucky draw and lottery..

First of all congrats for your new project. I remember when you launch it last year, now I think you relaunch the site.
Isn't it better if you put default jackpot at first and it raises when more people participate? That way people show more interest to the game.

Thank you Zz for your post, we are also considering about the new year lottery.

Regarding to bigger jackpots, it is calculated automatically depending on how many players contributed to lottery. The more players, the bigger jackpot

1st Winner (Jackpot): 37.5% of total contribution
2nd Winner: 18.75% of total contribution
3rd Winner: 9.3750% of total contribution
4th Winner: 4.6875% of total contribution
5th and 6th Winner: 2.3438% of total contribution

Good luck with your new service Aliser. I'm trying this, I hope my luck helps me. I wish we would see bigger jackpots in the future. You might also open a special jackpot for new year lottery, what do you think?