A lot of papers about cryptocurrencies explain the concept of the "longest chain", which goes along with these kind of figures:
I was wondering if there exist any kind of visualisation tool for these kind of discarded block chains within Bitcoin itself? There are a lot of visualisations available for transactions, but I'm interested in the amount of block chains that did not make it into the final blockchain (blocks that were discarded because they were no longer the longest chain).
There are several sites that maintain this information, and Bitcoin Core can be asked about it using the getchaintips RPC command.
It is however important to know that such information can never be guaranteed to be complete. Nodes only relay new blocks that are part of the (new) best chain.
A fork appears when two blocks are produced at approximately the same time. They both propagate across the network, and one part of the network sees block A first, and another sees B first. Assuming A eventually wins (is extended first), nodes that saw A first and were not connected to a peer that accepted B first, will never see B.
