A simplified flow of what happens during a fork war when the majority of hashpower mines for legacy node consensus rules
- incentives: no change required by miners, retain same pay structure
- disincentives: risk of being in the minority could lead to reduced effective value of a block win (true for both sides until a clear winner emerges)
And here is a version of what could happen if the majority of hashpower mines blocks for the new UAHF, but without clear dominance. In this case, approximately 75%.
- incentives: safest option to ensure payout until majority hash and strongest chain identified, fewer valid transactions in mempool needing sorted
- disincentives: foregoing higher pay, performing more (but fairly negligable) compute to filter.
At Block E, the alternate is 2 blocks behind in length, and doesn't that length until block H as depicted in this sample. This is illustrative only and obviously cannot project actual block production and adherence to rules. The purpose of this is to help illustrate how a chain that _may_ eventually win, could be multiple blocks behind in length.
The outcome takes much longer and potentially several blocks behind for the UAHF before catching up and surpassing to be the dominant fork the closer the majority is to just over 50%. Any condition where the alternate consensus rules for the UAHF are in the minority fork off as the weakest chain.
View quoted note →
If you aren't running a node (maybe plan on that...), you can also see fork info at 
