An Analogy on Bitcoin Mining

[Kakashi2020]

Say I tell three friends that I'm thinking of a number between 1 and 100, and I write that number on a piece of paper and seal it in an envelope. My friends don't have to guess the exact number, they just have to be the first person to guess any number that is less than or equal to the number I am thinking of. And there is no limit to how many guesses they get.

Let's say I'm thinking of the number 19. If Friend A guesses 21, they lose because 21>19. If Friend B guesses 16 and Friend C guesses 12, then they've both theoretically arrived at viable answers, because 16<19 and 12<19. There is no 'extra credit' for Friend B, even though B's answer was closer to the target answer of 19.

Now imagine that I pose the 'guess what number I'm thinking of' question, but I'm not asking just three friends, and I'm not thinking of a number between 1 and 100. Rather, I'm asking millions of would-be miners and I'm thinking of a 64-digit hexadecimal number. Now you see that it's going to be extremely hard to guess the right answer.

Not only do bitcoin miners have to come up with the right hash, but they also have to be the first to do it.

Because bitcoin mining is essentially guesswork, arriving at the right answer before another miner has almost everything to do with how fast your computer can produce hashes. Just a decade ago, bitcoin mining could be performed competitively on normal desktop computers. Over time, however, miners realized that graphics cards commonly used for video games were more effective and they began to dominate the game. In 2013, bitcoin miners started to use computers designed specifically for mining cryptocurrency as efficiently as possible, called Application-Specific Integrated Circuits (ASIC). These can run from several hundred dollars to tens of thousands but their efficiency in mining Bitcoin is superior.

Today, bitcoin mining is so competitive that it can only be done profitably with the most up-to-date ASICs. When using desktop computers, GPUs, or older models of ASICs, the cost of energy consumption actually exceeds the revenue generated. Even with the newest unit at your disposal, one computer is rarely enough to compete with what miners call "mining pools."

A mining pool is a group of miners who combine their computing power and split the mined bitcoin between participants. A disproportionately large number of blocks are mined by pools rather than by individual miners. Mining pools and companies have represented large percentages of bitcoin's computing power.