Learn English – Usage of the phrase “Eat your tea”

In British English, take a punt means bet; it is an informal phrase, though.
Its origin is early 18th century, from French ponte ("player against the bank"), from Spanish punto ("a point").

In Australian, take a punt is an informal phrase for "attempt to do something."

As David M suggests it is due to pluralization.

Americans tend to name their teams in reference to the collection of players on the team as a group. "The Yankees" or "The Red Sox" references the collection of players and managers who make up the team. A player is a Yankee, or a Red Sox, and the collection of players are "The Yankees".

European football team names tend to reference the club as a single entity. "Arsenal" is the name of the football club, the club is considered a single thing that exists independently to the collection of players, staff, etc.

But people will often refer to "the gunners", in reference to the current Arsenal players of the team when they want to talk about the collection of players.