<P> The new body had direct jurisdiction over several state leagues . Rule changes in this era included: </P> <Ul> <Li> 1922--Free kick for forcing ball out of bounds introduced . </Li> <Li> 1930--One reserve player introduced . </Li> <Li> 1939--Boundary throw - ins re-introduced . Dropping the ball included in holding the ball . </Li> <Li> 1946--Number of reserve players increased to two . </Li> <Li> 1969--Free kick for kicking ball out of bounds on the full . </Li> <Li> 1973--Establishment of centre square and restrictions on positions at centre bounces . </Li> <Li> 1976--Second field umpire introduced . </Li> </Ul> <Li> 1922--Free kick for forcing ball out of bounds introduced . </Li> <Li> 1930--One reserve player introduced . </Li>

How many players can stand the mark in afl