I agree. 4 v 4 is the smallest format that still provides width and depth in the game. 4 v 4 has 4 triangular combinations while 3 v 3 has only one. It's better for young players to learn while playing 4 v 4 games.
Sorry. I cannot respect any advice to assign positions in 3v3 soccer for kids--i.e., developmental play--I don't care who says it or writes it. That is so counterproductive.
Agree with JohnR. The first time my son played 3v3 his team got clobbered playing man to man. They switched to the 1 man back and went on to win the tournament (a Kick-It). One thing to ad, be more aggressive on throw-ins as you have a temporary numerical advantage. If your team is fast they can make a steal with a quick opportunity to score. His team would make as much of a third of their goals on throw in steals. Don't be afraid to shoot.
My daughter's club plays 3v3 futsal pick-up games as training every winter. Using the futsal ball really puts emphasis on individual skills, both passing and individual. I always see a significant positive change in her club team in the spring after a full winter of 3v3 futsal. (u11)
Why not just move to 4v4. 4v4 is the smallest manifestation of a real match. In it are all of the elements necessary for children to experience real soccer without any confusing duplication. In a real soccer match children have the option of passing the ball forwards, square or backwards. Three children cannot do this because one of the directions will be missing. While 3v3 is a valuable tool for young children and learning technique, it is limited in its use as a tool for the positional game. With five children the extra one duplicates one of the elements. He becomes "also wide, also deep or also back." This "also" position clutters the picture. 4v4 also provides the minimum numbers needed for all of the principles of play. One player is up top for penetration. Two are needed for width and one holds back to supply depth. Three cannot do this; one of the principles will be left out. With five, confusion will result as the "also" player gets involved when they change positions, which is called mobility. In 4v4 the responsibilities are very clear. All tasks are covered and none are shared which keeps things simple. Four v four is the optimum number for teaching in small-sided games. It has all of the necessary elements without any duplication.