The actual way to do it is to go back in exponentially larger steps until you reach a good commit. 1, 2, 4, 8, ... Then you already know that the bad commit is

The actual way to do it is to go back in exponentially larger steps until you reach a good commit. 1, 2, 4, 8, ... Then you already know that the bad commit is between 2^{k-1}st and 2^{k}th commit.