The 1985-86 Boston Celtics had great team chemistry. In winning the 1986 NBA championship, they may have been the best NBA team ever.
The 2004, 2007 and 2013 Boston Red Sox had great team chemistry. In each of those years, they won the World Series.
The 2001 New England Patriots went 5-5 during the first 10 games of that season. They never lost again that year, which means they won Super Bowl XXXVI. They won it again in 2003 and 2004, and played in Super Bowls XLII and XLVI. Each of these teams had great chemistry.
The 1981 and 1988 Cincinnati Bengals played in Super Bowls XVI and XXIII. Though they came up short both times against the San Francisco 49ers (coached by Bill Walsh and quarterbacked by Joe Montana), they had great team chemistry, including some of the best players to ever wear a Bengals uniform.
Chemistry is hard to define and even harder to understand. Sometimes, it is a matter of choice, but more often it is a matter of chance. It just happens. More often than not, it is either there — or it is not. But when it’s there, it’s the greatest feeling in the world.