Quote from: organofcorti on March 02, 2014, 10:51:59 PM

Quote from: Trefdraeth on March 02, 2014, 09:15:15 PM

Quote from: EdB666 on March 02, 2014, 07:21:47 PM

Quote from: gourmet on March 02, 2014, 05:35:46 PM

By extremely short blocks, you can't account for mean orphan probability. By a two-second block, probability of orphan race is extremely high, near to 100% IMHO, as the time differences between the good and the orphaned block normally are of the same size as is the block duration by a 2-second block. So I think you must leave out your "60" multiplier.

Good point - the odds still work out at around 1 in 1000000, but as Terry Pratchett once wrote, million-to-one chances happen nine times out of ten.

I still wonder if the contents of some blocks can make the difficulty vary significantly from the assigned difficulty though. Perhaps there is a weakness in (double) SHA256 where hash collisions are more likely with certain values?
Maybe OrganOfCorti can help us out on this one? Any crypto experts around? Where's Bruce Sterling when you need him...

OOC is the man, he will elucidate....

Thanks for the vote of confidence guys, but I'm having trouble following the question and answers. Can someone boil post a precis of the question?

EdB666 tried to calculate the chance of invalid block (orphan race) by a two-second block.
He started with the chance of two pools finding a two-second block at once, being the chance of one pool finding a two-second block (1/1000) squared, i.e. 1/1000000. For the purpose of finding the chance to one being an orphan, he multiplied this number by the chance for any block to be orphan, which he found to be ~1/60.
I disputed that the last step couldn't be applied for extremely short blocks, as there the chance for orphan is much greater, near to 1, as the block duration approaches the usual time difference between orphan and regular blocks.