A more recent change to help speed-up the game is to do with substitutions. Players originally had to come off at the halfway line on the same side as the substitute was coming on. Presumably this was to stop teams simply subbing a player on without one potentially coming off. Meaning that the team that had made the substitution would now have an extra man on the field. In the early stages of when substitutes were allowed there was not as many cameras around and the support for referees was not as good as it is now. So, the traditional system was an easy way to keep track of who went off and who was coming on to replace them.
This, like the multi ball system had its own issues. Substitutes are often used as timewasting methods by teams. Players being subbed on in the final 5 minutes of regulation time or even stoppage time can hardly be assumed to make much of an impact. They do however often waste a good minute or longer in game time. Especially if the player is coming from the far corner of the ground and decides to walk off at a very slow pace.
In response to this referees, can be seen jogging the player off themselves, even going as so far to brandish yellow cards for timewasting if the player continues to take to long.
Under the new rule though, players must now exit the field at the nearest sideline. Therefore, reducing the slow-motion stroll of the pitch of some players. This drastically reduces the amount of time substitutes can waste time, instead of walking up to 70 meters if they were in the far corner, they would simply be instructed to walk off the one meter to the nearest touchline. Now there has been some confusion with this, some players still try to come off at the traditional spot, but these are just teething issues as players adjust rather than actual faults in the system.