Inside look at the Chicago Cubs' epic comeback

You gotta have character! That's the secret sauce that won the Cubs their first World Series in 108 years, says team president Theo Epstein

Preview: Theo and Joe

Character is the difference maker.  And once the Chicago Cubs put together a team with it, and a good deal of talent, they won the World Series for the first time in 108 years. That's the secret to the Cubs incredible championship, says the team's president Theo Epstein.  Bill Whitaker speaks to Epstein, manager Joe Maddon and teammates Kyle Schwarber and Jason Heyward for the inside look at a sports story for the ages.  Whitaker's report will be broadcast on 60 Minutes Sunday, May 7 at 7 p.m. ET/PT.

Epstein, who helped the Boston Red Sox win their first World Series in 86 years, built the Cubs with young hitters who had character. "Players that tend to respond to adversity the right way and triumph in the end are players with strong character.  If you have enough guys like that in the clubhouse you have an edge on the other team," he says.  "I just saw over the years that the times that we did remarkable things, it was always because players didn't want to let each other down.  Players wanted to lift each other up," Epstein tells Whitaker. How does he know they have it?  "Find out how he treats people when no one's looking. You go talk to their girlfriend...their ex-girlfriends.  You go talk to their friends...their enemies," says Epstein.

Epstein brought Schwarber to the Cubs because he had character.  "He would run through a wall in order to catch a ball. He would attack any obstacle that faced the team," says Epstein.  The slugger tore knee ligaments early in April last year and was supposed to be out for the season. He was determined to make it back sooner. To everyone's surprise his doctor cleared him to play just in time for the World Series. But it was risky.  "He's like I'm not going to hold you back, but I could blow out, a hamstring, or an oblique by trying to do this," Schwarber recalls.   "And I was like, "That's fine.  I got the whole off-season to take care of it."

It came down to Schwarber, who hadn't batted in six months, trying to get back his stroke and eye only a few days before the World Series - all while doctors limited him to 60 swings a day.   He took his 60 swings, but also stood in front of pitching machine watching hundreds of pitches to retrain his eye.  He batted .400 in the World Series and got the hit that set up a dramatic win in extra innings of the final game.   But it took another act of character from another teammate to set him up.

Jason Heyward had a tough season, batting just .230. In Game 7, when the Cleveland Indians scored three times to tie the Cubs in the eighth inning, the team was down. Heyward called a meeting during a rain delay after the ninth inning, something the Cubs hadn't needed all season. "I didn't know what to say.  I just told them that I loved them. I said, 'We are the best team in the game...'" Heyward tells Whitaker.  Then character kicked in says Schwarber.  "You could feel that energy in that room to where it shifted from...being dead to we're going to win this game."