All players are individuals with differences. The development of children and young people is not linear and does not happen at the same pace for everyone. Quite on the contrary, players' physical, mental and social development often takes place at a different pace among the players in your team. Therefore we need to look at a more comprehensive way of looking at your players' age and development, taking both chronological and biological age into account. Learn more about chronological and biological age, and what you need to think about as a football coach, in this video.