Pragmatic definition of consensus for light clients

The discussion around the Bitcoin Cash (BCH) fork highlights a significant hash power battle between BCH and Bitcoin (BTC). This contentious split resulted in fluctuating hash rates for BCH, where it occasionally overtook BTC, reaching as high as about 60% of the combined hash rate on certain days. However, cumulatively, BCH's share peaked at approximately 12% of the total BCH+BTC hash rate before seeing a general decline.

Graphical data further elucidates the behavior of BCH's hash rate post-fork. The cumulative work after the branch indicates that while there were instances of substantial increase, the overall trend saw BCH struggling to maintain a consistent lead in hash power compared to BTC. The weekly and daily distribution of hash power showcases more detailed fluctuations, with certain weeks and days experiencing sharp increases likely due to temporary shifts in miner support or strategic responses to the difficulty adjustments inherent in BCH's mining algorithm.

This volatile behavior underscores the challenges faced by forks in gaining and maintaining miner support against a more dominant original blockchain. It also reflects broader market dynamics and miner incentives, which can shift rapidly based on profitability and network stability considerations. Such insights are valuable for understanding the security and economic implications of forks within the cryptocurrency ecosystem.