I recently had a look at BC.Game provably fair system. When I checked their crash game provably fair system, I found that the crash game doesn't satisfy provably fair criteria. I am not sure if they overlooked this part, or they intentionally trying to deceive users, so I messaged their customer support, who told me he will inform their developer to have a look. After quite some time, one of their support (or developer?) replied back to me, saying since it is a multiplayer game, their crash game doesn't need any client seed, unlike their individual games.
From this point, it is fair to say that they either 1) don't understand fully how provably fair works, in which case they should really stop the game until they understand it, or 2) they are trying to deceive players, especially BitcoinTalk users into having false sense of security.
As you probably know, any provably fair system will need some sort of client seed not known/ unguessable and cannot be controlled by the casino, to ensure the results are random and not known to the casino beforehand. BC.Game only uses the 10 millions server hash to generate the result without any client seed. This gave them opportunity to know all the bet results chain beforehand, and could keep on searching for a hash chain that would generate a results chain favorable to them.
Their verifier code (
https://bcsnproject.github.io/bcgame-crash/) shows that they didn't use client seed, and when you entered the game hash it output the correct result, meaning they are using this code without client seed to generate result. On other hand, their BitcoinTalk page (
https://bitcointalk.org/index.php?topic=5088875.80, page 5) shows that they uses client seed of Block 582,678, but if you were to run this code with their game hash, it doesn't output the same result.
I have used third-party software to archived their website and all info. This is done so that 1) if they have changed their website info I still have a record to show, and 2) prevent them from saying I changed their website info such as using google inspector, since the info is captured by third-party which can't be changed.
Below are some screenshots for your info. You can check them yourself by visiting their website, until they changed their website info and code.