also pools wont just jump straight to 2mb on activation day. pools will try a 1.000250 block and see the orphan risk.
Possible, but I doubt it. Part of the fork dynamics is dependent upon BU delivering greater value. If BU forks at 75%, then the 1MB chain will be about a 40 minute average block time, delivering 25% of its pre-fork throughput. With a corresponding rise in fees due to the rise in blockspace supply. The BU chain will be about 13 minute average block time. If BU stayed near its pre-fork block size, its throughput would be on the order of 76% of its pre-fork throughput. If, however, BU went straight to 2MB, then it would deliver 150% of its pre-fork throughput. With corresponding drop in fees. Blowing through the backlog in relatively short time. Cheaper transactions, more transactions: greater value. Leading to increased incentive for fence-sitters to throw in to the BU side.
Future increases may be more probing, and therefore incremental. But I would expect the 2MB immediately. They'll fall after the backlog is cleared.
the maths does not work that linearly.
EG if there are 4 pools of equal hash. it does not mean take one away and the time moves to 20 minutes. because the competition may have only been only seconds behind getting their own solution.
bitcoins are not mined based on the combined hashpower of the network. each pool makes their own effort. and the "75%" you mentioned is not 1 pools.
here this image will make it a bit clearer
http://i.imgur.com/tcAFVCH.pngas you can see 75% of blocks is just HALF the network hashrate in this example,(top half of image) but the block
timings still are reasonable whichever way you play it(bottom half when they have split)
Well, no, it does not make it clearer. However, it is peripheral to my point. Which is that it is unlikely that BU miners will creep up initially. They will likely go straight to 2MB. For as long as it takes to clear the transaction backlog. For such would deliver a demonstrably better user experience (faster cheaper transaction processing) relative to the other chain.
Yes, further increases may be likely to be more incremental in nature.
