Add four three year olds.
Preferably two boys and two girls.
Put one child in each corner of the field.
Add fencing to the boundaries of the field so there is no escape.
Upon blowing of an air horn tell kids to RUN! Where ever they want, as fast as they want.
It is almost guaranteed that two of these kids will crash full speed in to each other.
The second guarantee is that one of them will be my daughter.
