Union focused on their principles instead of matchups ahead of Game 2 with Fire

CHESTER — When the Chicago Fire picked up their first playoff win since 2009 a week ago, they picked apart Orlando City with a standard 4-3-3 formation.

When they visited Chester four days later for Game 1 of a best-of-3 playoff series with the Philadelphia Union, Fire coach Gregg Berhalter morphed them into what was listed as a 3-4-3 but looked functionally like a 5-4-1, with the wingbacks restrained in their ability to go forward.

That differed from the 4-3-3 the Fire used when the team got bludgeoned in Chester, 4-0, on Aug. 23. And it wasn’t the 3-4-2-1 — absent their prime playmaker, and with ostensible winger Maren Haile-Selassie bombing down the flank as a wingback — utilized in a signature 5-3 win at Inter Miami Sept. 30 to clinch their first playoff berth in nearly a decade.

Al