"The only thing I can say is we both have a great desire to win, to achieve, to be successful, to get the best out of our people," Ditka said. "That's what I tried to do, that's what he is doing."
The NFL coach who brought out the best in Harbaugh was Ted Marchibroda. The two of them helped get the Colts within one play of a Super Bowl appearance during the 1995 season.
Harbaugh began that season on the bench, and when he got his chance to play, Marchibroda told him to "let it rip." The words changed Harbaugh's mindset, and the Colts' fortunes.
"I see some of that in how he has handled Alex Smith," Jack Harbaugh said of the former No. 1 pick in the draft who has played his best football for Jim. "It's, 'I believe in you. Just go out and let it rip.'"
Al Davis, the iconic late owner of the Raiders, would allow Harbaugh to let it rip as an NFL coach for the first time. He hired Harbaugh as an offensive assistant in 2002 and exposed him to all facets of coaching and football administration.
Davis taught Harbaugh how much work it took to be a coach.
"Al challenged him, and Jim did all the grunt work," Jack Harbaugh said of his son, who often slept on a cot in the Raiders facility.
No man was more instrumental in molding Harbaugh's coaching philosophy than the late 49ers coach Bill Walsh. They never worked together, but Walsh, a former Stanford coach and consultant, endorsed Harbaugh for the Cardinal job. Over the last nine months of Walsh's life, the two would meet once or twice a month for a long lunch.
Walsh would draw out plays and tell Harbaugh about the history of the West Coast offense. How a play came about. How it evolved.
Harbaugh, pen in hand and tape recorder rolling, soaked all of it up.
"Part of his genius is he was very open about what he knew about football," Harbaugh said. "Knowledge is a powerful thing in professional sports, it's intellectual property. People try to keep others from knowing that. He was very open about sharing what he knew with assistants and people he cared about."
When Harbaugh became coach of the 49ers, he found the team and NFL Films had video libraries of Walsh coaching and installing his schemes. Harbaugh spent hours upon hours studying them.
"It's a tremendous resource," he said. "He was a master teacher."
Harbaugh has been blessed to learn from some of the best. But there also is something inside him that has made him who he is as a coach.
"I don't think I ever played with anyone at any level who is more competitive than Jim," said Tom Waddle, Harbaugh's go-to receiver with the Bears.
When Harbaugh faces his first NFL team for the first time Monday night, the Bears are likely to get a reminder of that.