In the world of leadership development, finding the right executive coach is often a matter of chemistry. We often introduce a coachee to two, sometimes three prospective coaches with the hope that one of them will click with the client. So much of a good coaching engagement is the willingness of the coachee to be vulnerable, to allow him or herself to open up and trust the coach. The greater the openness and trust, the greater the commitment of the coachee to change.

The same is likely true in the world of high-performance sports. Not every coach is right for every athlete. While Bobby Valentine‘s cerebral, in-your-face managerial style was perfect for the World Series bound 2000 New Mets, it was awful for the 2012 Boston Red Sox. While Soichi Sakamoto‘s my-way-or-the-highway approach to coaching championship swimmers was perfect for two-time gold medal-winning freestyle swimmer, Bill Smith, in the 1930s and 1940s, it was anathema to fellow Hawaiian swim star Halo Hirose.

When Wayde Van Niekerk of South Africa blew away Michael Johnson’s 19-year-old world record time in the 400-meter sprint at the 2016 Rio Olympics, almost everyone was surprised to learn that his coach was a 74-year-old woman whose white-haired, grandmotherly appearance fooled security at the Olympic Stadium. They would not let the woman see her prodigy, Van Niekerk. After being reassured profusely by fellow South Afrikaner athletes that Anna Sofia Botha was indeed the coach of Rio’s newest star, the coach finally got to see her coachee.

As she explained in this New York Times article, “we just hugged each other. It wasn’t necessary to say anything. We knew in our hearts and in our minds what we thought and what we had achieved.”

Van Niekerk met Botha in 2012, when he enrolled at the University of the Free State, where Botha was the track coach. Even though she seemed to appear out of nowhere, Botha has actually been coaching track for nearly half a century, after competing in track herself. So when she saw this raw talent come to her, and saw a sprinter prone to leg injuries, she recommended that van Niekerk switch from the 200 meters, to the 400 meters, under the assumption that the longer distance would place less stress on his hamstrings.

“I have such a big responsibility to get this athlete to develop to his full potential, and also the responsibility for myself to try to do my very best not to do something wrong which can make or break him,” Botha told the Sunday Times (cited in this Deadspin article.) “The main thing is we listened to what his body said to us. If the body said stop, we stopped, or went a little softer.”

“She’s an amazing woman,” van Niekerk said in this article in The Guardian. “She has played a huge role in who I am today and kept me very disciplined and very focused on the role and who I need to be.” Clearly Niekerk needed someone who could bring the tough love, and Botha confirmed that in the same article.

“I dearly love all my athletes but it’s about being strict … We can laugh, but when we have to work hard, we work hard.”

World-class athletes who self-coach, like javelin champion Julius Yego, are few and far between. The coach can sometimes have a huge impact. Who is the right coach? Well, if you’re serious, you probably should not settle for the first one to come along. The coach right for you is out there. You’ll know it when you meet her.