Quote from: drazgor on June 12, 2013, 11:30:28 PM

Quoted from the bitcoin site:

Quote

The difficulty is the measure of how difficult it is to find a new block compared to the easiest it can ever be. It is recalculated every 2016 blocks to a value such that the previous 2016 blocks would have been generated in exactly two weeks had everyone been mining at this difficulty

So a difficulty increase every 11 days seems a bit odd to me.

If the hashrate is constantly increasing, then difficulty will always lag since it's based on the previous 2016 blocks, not the upcoming future 2016 blocks. So there will be periods when many more or many fewer than expected blocks are solved. For example, last week over 1300 blocks were solved. If difficulty wasn't lagging, then only 1008 blocks would have been solved (ignoring variance).