[nosuchthing]

Bitcoin mining = "Guess a random number between 1 and 5"

If the network guesses too fast due to more cumulative guesses per second, the target number increases.

Interesting historical antidote, in early November of 2017 there was an event where it became more profitable to mine Bitcoin Cash. During that time about 60% of the miners left BTC Core in unison to focus on BTC Cash. Transactions for BTC Core started taking upwards two to three times as long as there wasn't enough hash power to guess the magic number in time.

Eventually the miners returned to mine BTC core and transaction times returned to normal, other than the backlog in the memory pool that built up during that period.

[SilasX]

BCH is frequently more profitable than BTC -- the mining power constantly oscillates between the two.

Checkout fork.lol which tracks DARI, an estimate of the profitability of mining the coin, you see how the more profitable one frequently switches:

https://fork.lol/reward/dari/btc

[rory096]

This is of course not surprising - in the long run all difficulties (for similarly hashed coins) should trend towards equalizing profitability lest they create an arbitrage opportunity. The driving factor in the grandparent's case was the short-term spike in BCH after it was listed on Coinbase.

[nosuchthing]

Not entirely. There was a flaw/feature in the difficulty algo for BTC Cash that allowed miners to generate a significant quantity of blocks very rapidly.

https://news.bitcoin.com/bitcoin-cash-hard-fork-plans-update...

[chocolatebunny]

well that's an interesting top level domain.

[ilovecars2]

The excessive mempool size caused a lot of trouble for us when attempting to read it from bitcoind. Since the mempool was so large, JSON-RPC requests were taking upwards of 15-20 seconds. I’m surprised such a critical endpoint is so sub-optimised.

[simias]

I never understood why the people behind Bitcoin Cash didn't "manually" lower the difficulty at the forking block. This would've been a strong incentive for miners to mine the fork and could've been good publicity. Instead most people didn't bother to mine the least profitable fork which had the same difficulty as the "main" chain. That resulted in a few chaotic days where almost no blocks were mined before the difficulty automatically and slowly adjusted.

[nosuchthing]

They did modify it