all i wanted was anomaly 2 <| sep |> Only people who matter are miners . 51 % of hashing power can force any fork . You don ' t need 51 % to fork . You can do it by yourself if you ' d like and if you could figure out how . But when we are referring to forking , we are talking about a fork that hopefully results in the original chain dying simultaneously with the new chain . Otherwise , most would consider the fork unsuccessful . The contentious ETH fork failed at this with over 99 % hash power . Then hash power switched back after the first difficulty adjustment made it more profitable to mine on the original chain . Even the most pro hard fork developers know that if only 51 % of the Bitcoin hash power tried to fork , it would result in two chains . Of course , market value would not switch , and the hash power on the new chain would move back to the profitable chain .