Like Cassidy, Cora and Stevens also heaped praise on Belichick, as all three marveled at the future Pro Football Hall of Famer's ability to preach discipline and accountability.
"Not beating yourself," Cassidy said when asked for the most important piece of advice he learned from Belichick. "I've been a big believer in that as a coach. You coach discipline, you can hold people accountable with their discipline. Talent levels change from team to team, but I thought he was real good with that, how he really enforces that part - we're not gonna beat ourselves, we're gonna go out and play well, but it's not gonna be looking in the mirror and going, 'Geez, we weren't prepared to do this or in this situation.'"
Cassidy noted that his ability to enforce similar values is made far easier by having such a respected veteran core - highlighted by Patrice Bergeron and Zdeno Chara - already in place.
"The Patriots have been the best at establishing culture - this is the way we're doing it, we're gonna get it right," said Cassidy. "If you're not on board, that's fine. We'll get someone else that is. It's worked for them very well. Credit to Bill, credit to ownership. It usually starts at the top and that direction.
"We have it with Bergeron and Chara - we're very lucky. I'm one of the most fortunate guys in the National Hockey League to coach true pros like that. Coming in at a young age as I did, I appreciate that.
"I'm sure Brad has his guys that he leans on and Alex the same…[Bill's] done a great job, him and Tom [Brady], obviously the two faces. It's been terrific."
Belichick tried to deflect the admiration - jokingly saying, "what is this a roast?" - before going on to discuss the strong relationships he has built with Boston's coaches during his 20-year run in Foxborough, dating back to former Celtics head coaches Rick Pitino and Doc Rivers, former Red Sox manager Terry Francona, and former Bruins head coach Claude Julien.
"I've had a great relationship with all the coaches that have come through here," said Belichick. "The sports are different, but sports are sports and competition is competition. I think what we all love about the City of Boston is the passion our fans have for pro sports…all those organizations have been very supportive of us and we have [been] the same way.
"They take great care of our players and staff when we come to see them play; we try to reciprocate on that. Championships that they've won we've been able to celebrate with them together and they've celebrated with us. It's almost like a college relationship where the coaches and the teams at the school are all playing for the same alma mater. It's similar to that here.
"Our players and other players from the Celtics, the Bruins, the Red Sox…some of them are very close or know each other…it's a close knit group."
And a group that certainly feeds off of each other's achievements.
"We've looked at the success those teams have had," said Belichick. "Certainly the Red Sox last year had a great season and we try to learn from what they did, how they did it, and the success that they had. Or the Bruins last year throughout the season and how well they played throughout the playoffs and latter part of the season. We learn a lot from them…I've learned a lot from all three of those coaches and organizations."
During his visit to Fenway Park, Cassidy also presented a check to the Jimmy Fund for $25,000 on behalf of the Jacobs Family, the Boston Bruins, and TD Garden. Bruins goalie Tuukka Rask and defenseman Matt Grzelcyk were among the other Boston sports figures to attend the two-day event, which raised $3.4 million.