Why are substitutions limited?
I believe the questioner is comparing soccer to other sports such as football, hockey and basketball, which have unlimited substitution systems. There are some junior versions of soccer that allow unlimited substitutions though, primarily for development reasons. My local club does that in its academy and recreational programs. The answer is that the nature of the game really prohibits it (this is also true of rugby, BTW, which has even tighter substitution limits). The one poster was right in that unlimited substitutions would disrupt the game badly, although if this were to be allowed, the rules would also have to be changed to stop the clock for subbing in and out, but that would just increase the disruption. Moreover, unlike football, which is the nearest comparable sport with unlimited subs, the matchup in soccer or rugby is not offense v. defense, it is a balanced team combining offense and defense against a similarly balanced team. The use of substitutions will of course adjust
