HAVERHILL, Mass. — Tom Brady is now acclaimed as the greatest quarterback in the history of the NFL, and a North of Boston/Northeast teen known as the “Sign Kid” just might be a contender for the title of greatest Boston sports fan.

Jason McKeon, 15, has attended most of the victory parades for Boston sports teams for the last decade and a half — including five for the New England Patriots, three for the Boston Red Sox and one each for the Boston Celtics and Boston Bruins.

When he attends these celebrations, he carries a sign that proclaims his age and the number of victory parades he’s attended. The 2017 edition of the sign, 30 by 20 inches, reads “15 years old, 10 parades.”

McKeon attracted the attention of The Boston Herald at Tuesday’s parade and he’s been interviewed by The Boston Globe and other newspapers on previous trips.

The latest victory parade was really special, he said, because it highlighted “the realization that anything is possible”, which the Patriots proved during Super Bowl LI.

At halftime, the team trailed 21-3 before making a surprising comeback and clenching victory with two back-to-back 2-point conversions followed by the winning touchdown in the first overtime in Super Bowl history.

McKeon’s father, Stephen McKeon, described the last 15 years as “the most spectacular period for Boston sports.” Before that unexpected first Super Bowl win for the Patriots back in 2002, New England fans endured many years of “droughts,” he noted.

Jason McKeon said he considers himself very fortunate to be living during a time when the Boston teams have achieved such success.

“It’s a huge memory,” he said. Stephen and Jason McKeon said they are now looking forward to a Celtics victory parade in June, a Red Sox World Series championship celebration in November — and the sixth Patriots’ Super Bowl win this time next year.

How about the Bruins? Not this year, they said.

Not just a fan, Jason McKeon is an avid sportsman himself. He plays basketball locally and is currently a three-season runner at his high school with plans to participate in the Boston Marathon when he reaches age 25.

For now, he said he likes math and will likely pursue a career in engineering or technology.

Tennant writes for the North Andover, Massachusetts Eagle-Tribune.