What athletes believe to be true is true for them, regardless of how it plays out in the real world. If a basketball player believes that watching a video of himself or herself making free throw after free throw after free throw will improve his or her accuracy at the free throw line, it will. Providing, of course, that he or she has the skill level.

Once when the University of Missouri football team was playing the University of Oklahoma, the Tigers were trailing by 21 points at half-time. But during the third quarter Oklahoma’s All-American quarterback sustained a game-ending injury and had to be carried off the field. His injury energized the MU offense which proceeded to score three touchdowns, only to lose the game by a single point. The Tigers’ offensive unit hadn’t changed, but their belief they could win did.

A particular belief can limit or enhance performance. A professional golfer may have played a particular course many times, yet feel a need to play the course one more time the day before a tournament. If the need is satisfied, it will aid the player’s performance.

A major league baseball manager may believe that his team will face a greater disadvantage from a wet infield than the opposing team will. His players will know that. The manager thereby establishes a self-fulfilling prophecy that excuses low performance. And to excuse low performance is to promote it.

Some athletes believe a particular number on their jersey is important to success. If they have the number, they have extra confidence that enhances performance. If the team manager assigns a different number, the player loses confidence and that loss is reflected in performance. A wise coach takes advantage of his or her athletes’ beliefs, no matter how crazy they may seem to be, in order to build a team’s strength.

The athlete’s belief system controls performance, not the coach’s. If athletes believe that being sexually active the night before a big game will make them more relaxed and that they will therefore perform better, they will – regardless of what their coach believes. Coaches often try to force their own belief systems on their athletes and it just doesn’t work. The best coaches, the most successful ones, are those who instinctively tap into the belief systems of their players and use those beliefs to the team’s advantage.

In matters of health, what a patient believes about the potency of a particular medicine or treatment is almost as important as the medicine or treatment itself.