Get To Work: With Suzy Welch

At home with Bill Belichick and his new best friend: a puppy named Nike

Nothing puts a smile on Bill Belichick's face like his dog Nike

I've met a lot of "superstars" in my career as a journalist — CEOs, tech wunderkinds, investment gurus — and one trait they all tend to share is an uncanny ability to control the conversation, especially when asked probing questions.

But I've also discovered there is one query that melts away all that restraint: "Do you have a dog?"

When the answer is "yes," it's a very nifty thing, because dogs can tell us a lot about their humans. I've seen it a hundred times.

Case in point is Bill Belichick, the extraordinarily successful — and famously reticent — coach of the NFL's New England Patriots. His post-game press conferences turn verbal and emotional minimalism into an art form.

But spend an hour with Belichick and his dog, an Alaskan Klee Kai named Nike, whom he shares with his longtime girlfriend Linda Holliday, and you'll witness a side of him usually only shared with family and close friends.

With his "little wolf" Nike by his side, Belichick is cheerful, warm and downright funny. The fierce guy in the hoodie is suddenly just a friendly guy in your neighborhood.

You see, Nike, Belichick explains, loves him unconditionally, as dogs do. He lives in the moment, doesn't care about football, and "is always in a good mood." 

Opponents on the gridiron may never see it, but Nike brings out the same in his own "Big Dog." All I had to do is ask.

Like this story? Subscribe to CNBC Make It on YouTube!

See also: More than 6,000 dogs 'work' at Amazon, where every day is 'Take Your Dog to Work Day'

Meet the dogs of 8 tech titans