When in the open field, two opposing players can both challenge for a
header. Most of the time as long as both are going for the ball,
there is no foul. I have been told many times that the 'official'
rule is you have to jump straight up and be going for the ball. If
you do not jump straight up or are not going for the ball, then there
is a foul called on you. What is the official rule regarding two
people challenging for a header? I have seen many people get fouls
because they came running in...even though they were going for the
ball and actually got the ball!