Make Indirect Kick Rule realistic

[ahasselbring]

At the moment, the indirect kick rule is a combination of two different concepts in real soccer:

• Indirect free kicks and throw-ins cannot directly score goals without another player touching it first. There is no differentiation between deflection and deliberate play (see this video for a throw-in goal that was only possible because the goalkeeper touched the ball).

• In all restarts of play, the player which brought the ball into play may not touch the ball again before it has touched another player. The rule book explicitly states for free kicks, throw-ins and corner kicks (here for the free kick):

  If a player, while correctly taking a free kick, deliberately kicks the ball at an opponent in order to play the ball again but not in a careless or reckless manner or using excessive force, the referee allows play to continue.

  The same is not stated for kick-off, goal kick and penalty kick, but in those situations it doesn't really make sense for human players. Therefore, in my opinion, we should not differentiate between deflection and deliberate play either.

I propose to adopt this in the SPL in the following way:

• From any set play (kick-off, free kicks including kick-ins, goal kicks and corner kicks, penalty kick), the kicker may not touch the ball again before it has touched another player. It does not matter if that touch was a deflection or an arbitrary play. When touching the ball again before it has touched another player, an indirect free kick is awarded (I suppose we can save the direct free kick for a handball offense for the next decade). The kicker does not get a penalty (besides a free kick against its team). This restriction only holds for the attacking team and continues to hold even if the set play timed out (i.e. you can't circumvent it by waiting 10s after the kick-off - see below for another way to handle this).
• Kick-offs, penalty kicks, goal kicks and corner kicks are direct (i.e. a goal can be scored directly), while kick-ins and other free kicks (such as pushing free kicks or free kicks that occur due to the first rule) are indirect (i.e. they cannot score a goal, but any touch of another player is sufficient, i.e. it need not be deliberate play).

From there on, a few other changes could be made that go towards a more human-like game process:

• If a set play times out (e.g. 10 seconds after kick-off signal, 30 seconds after free kick, 30 seconds after penalty kick signal), instead of declaring the ball to be in play, a free kick could be awarded (this is justified because in real soccer, it is an offense to delay the restart of play - on the other hand, admittedly, awarding a free kick is not quite correct because offenses during stoppages of play cannot change the way play is restarted or something like that). The fact that the ball can come into play without a player having touched it generally does not correspond to real soccer well.
• For kick-off and penalty kick, it's unclear to me to which state the time between the whistle and the ball coming into play should belong. Technically, the ball is not in play during that time, and therefore, the clock should be paused in the knock-out phase. A similar thing could happen with all free kicks given Set phase and whistle for free kicks #89. A quite radical step would be to count everything before the ball is in play to the set state, and remove the motion in set penalty (as Patrick suggested at RoboCup 2022).

PS: I don't care about any adverse effects that this rule change might have when there is only one field player left. In real soccer, the match would have been stopped long before (at least seven players must be on the field, which, scaled down to our numbers, would still be more than two players).