The Senior Division is for 15 & 16 year olds.  The Big League Division is for 17 & 18 year olds.  These divisions do not play until after the high school season is over.  Players must try-out and be drafted to a team.  Senior minimum play time is 1 at bat and 6 defensive outs.  There is no minimum play time in Big League.  A designated hitter is allowed in these divisions.  There is a 9 batter line-up with substitutions.  Games are 7 innings (mercy rule 10 runs ahead after 5 innings).  Time limits may be imposed for scheduling purposes.