Think about the community has solely 20 miners.
Segwit was activated solely when a minimum of 95% of the miners signaled help, which suggests in our case 19 of the 20 miners have upgraded.
The remaining miner will begin to see some unusual tx on blocks, the place anybody can spend.
If he spends a kind of tx after which tries to incorporate the spending tx in a brand new block, the opposite 19 will reject it, since for them it has an invalid tx. The immense majority of upgraded miners will stop the chain from forking.
When requesting blocks to its friends, nodes ship their software program model.
When our sole miner asks for blocks to its friends, they know he didn’t improve to Segwit, so that they ship him the block with out the witness, which have to be smaller than 1 MB, thus making the block legitimate in accordance with the outdated guidelines.
When an upgraded miner asks for a block to his friends, he receives the block with the witness, the place the overall have to be lower than 4 MB.
It’s a tender fork as a result of outdated nodes contemplate new blocks legitimate.
