Ajdin Kolonić is a tennis entrepreneur, mental coach and the author of “The Mental Habits of Winners: A Step-by-Step Guide to Becoming a Mentally Strong Tennis Player.” As a tennis coach and active player, Ajdin has spent the last decade studying sports psychology and contributing articles on mental strength in tennis. In his book, he presents his novel and complete model of mental aptitude in tennis, along with a clear program on how to mentally train. He is also the designer of two apps that support his methodology: Top Tennis Tracker and Inner Tennis, both of which are available for Apple and Android smartphones.