i think what max was getting at is, you can set your autofocus to shoot using a 'multipoint system' or a selective point.... most amateurs and laypeople will use the multipoint focus....that is what is screwing you up...it wont always focus on what you want. If you choose the selective autofocus system, you choose where what area you want to focus on .....check your camera manual!
on the other end of things, when it comes to manual and automatic...its really a matter of personal choice....some people can focus really fast...others' cannot....auto focus is fantastic for use on children and in general for that matter..."its not an 'oh my god a child photographer never uses manual".....hello, what do yuou think they did before autofocus cameras? when shooting sports children or anything fast in manual mode, you must know your subject, anticipate and pre focus and learn to work your camera quick!