On Saturday, the Vineyarders will take on the Nantucket Whalers for the 37th time in this storied rivalry for the Island Cup.

The rivalry game between the Vineyard and Nantucket football teams ended in victory for the Vineyarders, who defeated the Whalers 21-7 in a rough, penalty-filled game. Junior running back Jacob Cardoza scored two touchdowns.

For one day every year, the Island Cup trophy sits on the sidelines of a football field, where its home for the next year will be determined. For the other 364 days, the trophy sits in a case.

Martha's Vineyard needed a touchdown. Twenty-six seconds left on the clock. Archrival Nantucket up 26-21. First and goal, seven yards to reach the promised land of the Nantucket end zone. Vineyard quarterback Alec Tattersall walked toward the stands of Dan McCarthy Memorial Field, raising his arms over his head — get on your feet, Vineyard, on your feet. His teammates followed suit, arms lifted, encouraging, and the once-quiet crowd roared back to life.

In 1991, Jason O’Donnell was on Coach Donald Herman’s first state championship football team at the Martha’s Vineyard Regional High School. On Monday, Mr. O’Donnell is out on the field with the four other varsity assistant coaches alongside Coach Herman, helping the team prepare for the Island Cup this weekend.

When Charles McGrath wrote about the annual Island Cup game between the Martha’s Vineyard and Nantucket football teams for the New Yorker in 1984, he likened it to a fierce sibling rivalry. What mainland team could hope to drum up a rivalry as poignant with either of the Island squads? For all that the Vineyarders can’t stand about the Whalers, they also know that the only football team in the entire country that could possibly understand what it means to be an Islander is that of their brother-in-isolation, Nantucket.