I was incomplete in my research of this; do not take this as advice. The post read:
Some of you may think that this is "close enough". I'm sorry to crush your dreams, but it's not
a is blocks needed to lock in
b is blocks left until lock-in ends
m is miners who support BIP91 (the percentage divided by 100)"The current statistic being thrown around is that we need 80% percent of miners to approve the BIP91. Currently, according to https://www.xbt.eu/, 78.4% support BIP91 and 21.6% don't.
. What needs to happen is out of the remaining 312 blocks, 249 need to be mined by BIP91 miners. The likelihood of this happening is currently only around 30%. To adjust the calculations for current data, visit this calculator I put together: https://www.desmos.com/calculator/ymtfbk8boa
The formula was written using binomial probability"