What's the most championships Boston teams have won in one year?

Since 2004, Boston Has Won 18 Percent of the Four Major Sports Championships - Boston Magazine

Teams with the most World Series titles

NBA Championship Winners By Regular Season Seed: No. 1 Overall Seed Have Won Nearly 70% Of The Titles - Fadeaway World

Boston: City of Champions- the Decades of Dominance

Miami Heat Beat Boston Celtics in Game 7 to Advance to NBA Finals - The New York Times

The Celtics Got Lucky by Not Getting What They Wanted - The New York Times

Jerry York's BC teams played the game the right way and were at their best when it mattered most - The Boston Globe

Has your city won as many championships as Boston? - The Boston Globe

The Ultimate Boston Red Sox Trivia Book: A Collection of Amazing Trivia Quizzes and Fun Facts for Die-Hard BoSox Fans!: Walker, Ray: 9781953563170: : Books

Boston Celtics' NBA Championships: List by year of all the titles won by the Celtics

Lakers championships, finals appearances, history and more

Basketball NBA Teams Most Rings

Who has won the NBA every year? Full list of winners - AS USA

Consecutive NBA Championships: Boston Celtics, Lakers, Chicago Bulls