[rfp1234]

1986 Red Sox lose @ Mets Game 6 (capped by Bill Buckner error).

[Paisan]

1986 Red Sox lose @ Mets Game 6

This doesn’t qualify for the list. Remember, it was Game 6, which TIED the series at 3.
The Red Sox could have still won the series.
All they had to do was win Game 7.

They didn’t. The Mets were the better team that year.