"Limiting subs would increase the competitiveness greatly. Like star said, players would be constantly challenging eachother for starting spots."
What programs do you know where bench players do not care to challenge for a starting spot? I would like to transfer to this school so I could just rest on my laurels. As far as I have seen, it still means something to be a starter. Players take pride in earning a starting spot. Substition rules have nothing to do with it.
The posts on this thread make it sound like high school soccer is a substitution exhibition with a little soccer in between. Does this happen? Do coaches sub 6 or 7 people at a time? Do coaches sub after 10 minutes?
In a competitive contest, the starting 11 play the majority of the game. From what I have seen substitutions are made based on strategy or fatigue but when two quality programs battle it out, the players that have earned their starting spot also earn continued playing time by the play in the game. I would assume most are in match condition to play at least 70 minutes of the match.
In non-competitive contests, the players are still in match condition, they are not going to slow down because of fatigue. In some regions, as many as 40% of the games are a mismatch. Give the starters a run because they have earned the chance to play and then let the subs and JV players step have a chance.