According to whowins.com, NHL teams winning the first two games of a series at home have won 90.1 percent (191-21) of their playoff series.
If the Red Wings win tonight, the historic value of a 3-0 series lead for a team that started at home is this ... a 99.1 percent series winning percentage (115-1).
If the Red Wings lose tonight, the historic value of a 2-1 series lead for a team that started at home is this ... 77.6 percent (166-48).

In other words, tonight's game has a 21 percent swing in the Red Wings' chances of winning this series ... or from virtually locking it up to dropping to a 3-in-4 chance of advancing.