[kanzure]

> because that suggests you can tell that a block is a "forked block" the moment it's created, but you can't.

Invalid blocks are invalid, that's one way to tell. Run the bitcoin protocol rules and you'll get the same results as everyone else.

[PretzelPirate]

You often get two valid blocks at the same time, and whichever one gets the most blocks built on top of it wins.

[DSMan195276]

He's not talking about a hard fork, where blocks from the new fork are invalid on the old fork. He's just talking about two miners finding a new block at approximately the same time. They're both valid, but only one can become part of the 'main' chain, the other will eventually be lost as nobody continues to mine on top of it.

[phailhaus]

True, but I'm referring to valid blocks.