That's some serious gorilla math.
How on Earth is 88% @ 10-7 when there are 3, 7-5 teams. The Bills need to lose 3 of the their next 5 games because they beat us twice.
I think it's closer to a 4% chance if we finish 10-7.
This site shows 79% chance at 10-7. Either way the 88 and 79 are a lot closer to reality than your 4% number.
Hopefully this helps you understand.