The physical movements of children become smoother and refined through practice, training, and education. They become more skillful through co-ordination exercises and small-sided games, which are systematically included into their development process.
Professionals - who perform at the highest level - play in a 30-50 meters channel most of the time during their game – take a look at the picture on the right. Their goalkeepers are 10-20 meters behind them sweeping.

Players often – sometimes five on five in numbers - have to be able to create attacking possibilities (either individually or making short and quick combination passes), and finally to score using “small fields” with dimensions of 5x5, 10x10, or 20x20 meters. Today, someone cannot just learn how to play in such small areas by having a feel for it.
Children have to practice the different kinds of games in the appropriately sized fields and with the appropriate number of players for the right amount of time so the playing skills will develop at the right rate. If this complicated, but teachable learning process is left out of development, then players will be confused in tight areas and will perform uncoordinated movements and produce a boring game. Players who have never experienced such diverse training methods will play their games in a way that is pictured on the left: stretched and boring.