No. of Recommendations: 2
One of the links is regarding Bitcoin Gold, not Bitcoin itself. The other link describes how it's theoretically possible but has never happened...and if it didn't happen in the early days, it seems much less likely to happen given how widespread mining is now. Even if some blocks broke off to a new chain because a miner got lucky with 20-30% of the mining computing power, the chain can recover. I still don't see how any one entity could pull off 20-30% mining power, but I don't have a ton of knowledge on this.
