I write this after a great deal of uncertainty around the recent BTG Fork. A lot of people missed out because they followed a specific timer, and not the actual block creation. Blockchains are a distrubted public ledger. What this means is anyone running a node, whether it be a seperate piece of software, or built into the wallet, has a copy of the entire blockchain. That means, all the accounts and transactions that have ever happened. You can imagine some of the nodes/wallets are quite large. A standard bitcoin wallet, with ledger will run about 5gb’s. Ethereum’s is running around 3gb right now.
If you’re curious as to what an actual blockchain is, it’s basically just that. A bunch of blocks of data that contain the transactions that happened at that time, and any accounts created. They are almost always linear and sequential. So block three always comes after block two. All of these are usually stored in some SQL database.
To show you exactly what I mean, if you check out Rise Scanner you can see all the transactions that are happening, and down a little bit on the page, you can see the blocks that have been generated. You can click around and freely look at account balances and view transactions. This one is specific to the Rise blockchain, but all of the coins that use a public ledger, either have a scanner or at the very least, the ability to have one. You can see bitcoins Block Explorer, Ethereum’s at Ether Scan, and Ubiq’s at UbiQ Scan there’s hundreds of these sites.
As you can see, these viewers are everywhere, and are incredibly detailed. Once Rise Scanner went live, the community was able to identify a serious problem in the dPool software for payouts, allowing people to get multiple payouts a day for the same Rise. An example of one of those accounts is here: http://risescanner.com/acnt/4970986489826601037R/
So how can you put this information to good use? When events like the BTG Fork happen, you need to find out the Block the fork will happen on. In this case, BTG was 491407. Blocks are sequential so you know that 491406 is the one that comes before it and so on. There’s an upcoming SegwitX2 Fork for bitcoin at 494784. Don’t fool yourself by looking at count down timers. Blocks are generated anywhere from 3min-50min, so it’s impossible to give an accurate estimate.