Perhaps the nadir was the Patriots’ 1990 season. Behind the unlikely quarterback triumvirate of Marc Wilson, Tom Hodson and Steve Grogan, the Pats, who play down the road in Foxborough, Mass., were 1-15 and weathered a scandal over the sexual harassment of a female reporter.

But in the 21st century, it has been all Boston. The Patriots have five titles since 2000, the Red Sox three. The Celtics won it all in 2008 and the Bruins did so in 2011. Though the Revolution have not won the Major League Soccer playoffs, they have made the final five times in the century.

Boston’s run compares favorably to the best stretch by any sports city. With so many teams in the New York metropolitan area, a couple of them are almost always good. The highlight may have been 1969-70, when the Mets, the Jets and the Knicks all won. Chicago has two baseball titles (from two teams) and three hockey championships in this century, though it needs the Bulls and the Bears to improve.

The Lakers won five N.B.A. titles in the 1980s and the Dodgers two World Series. Philadelphia made the finals in all four major sports consecutively from May 1980 to January 1981, though it won only the World Series. The Pirates and the Steelers were consistently good in the 1970s.