Hi , just wondering if the first few posts being solved is why its showing 21G as next difficulty is happening because of cleaning house. It sounds to good to be true but I'd love some easy bitcoin for a few days. EclipseMC is on day 3 of a coin and I can't get payed anywhere till that difficulty balances out.
If you're looking at an app, such as my Pool Monitor app, that calculates next difficulty based on the number of blocks solved since the last diff change, that explains it all. Difficulty did just switch, and I think it decreased almost 1%.
The estimated next difficulty in my app projects what the next change will be IF the blocks/time solved since last diff change remain constant. Right after a difficulty change, that number is a bit erratic due to luck. It'll swing wildly all over the place, and then after about 6 hours, I'd guess, it'll get more realistic. And the closer it gets to the next change, the more accurate it'll be.
Note this is contrary to what most other difficulty prediction sites (that I've seen) at least do. They make assumptions based on prior increases, SWAGs, and crystal balls, none of which are entirely accurate.
Lastly, I think it's unlikely that it'll drop 35%. With the SP20 sales for black Friday weekend, I'd imagine difficulty will increase at least a little. But only time will tell, as there really is no accurate way to predict immediately after a difficulty change what the next change will be.
M
I find the BitcoinWisdom predictor to be fairly reliable. It doesn't swing too much. I don't know what algorithm they use, but it's resistant to at least some of the flaws that I've seen with others. I think it must use some kind of upward bias where it more heavily weights the most recently seen high-point for hashrate. This works on an intuitive level because while new mining hardware might be turned on for testing then taken offline while it's shipped out to customers, after a week or two it will tend to turn on and stay on permanently. So if the network hits a hashrate peak and then drops down, it's a safe bet that it will soon hit that level again.