Looks like the "0% luck for a day" has finally come to a close at 27+ hours. That was BRUTAL!!!!
I don't think it's luck. There's a pretty consistent pattern there where we have bad luck for that block if the pool hashrate is (10 + n*0.23-n)PH/s, where n is any positive integer. The block at 10.23PH/s was 20.5 hours, and the one at 10.45PH/s was over a full day. Lord knows what would happen if we actually hit 10.67PH/s, it could be a couple day long block.
I hope slush looks into this and can find the error in his code. These long blocks need to stop.
I know others had postulated that the pool was has having trouble "handling" over 10 PH, but you're suggesting there could be an error related to or caused by the formula you provided? Seems unlikely to me, as there is nothing obviously significant about the formula or the resulting numbers AND the fact that the pool hashrate is just an estimate of the total scoring hashrate (representing a rather wide range of numbers in terms of even GH (10^9 hashes per second) and rounded to the nearest 10^10). I guess my point would be the pool's scoring hashrate is too arbitrary of a number to likely be responsible for a glitch in the pool, if that makes sense.
My guess is just coincidence and occasional long blocks due to bad luck. Recent days have done a lot to disprove the original hypothesis of the pool being unable to handle hashrates above 10 PH, as the last couple of days have seen several blocks found over 10 PH AND 100% luck. Here's hoping the same will continue to happen.
My question is, where did 1 entire petahash suddenly appear from...? ~10.45 to 11.45!