[robocup-small] New Rules

[Christopher Head]

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Dear teams,
I’m happy to announce that the technical committee, with some
much-appreciated input from the organizing committee, has prepared the
new rules for use at RoboCup 2013. As always, these rules are available
on the league’s wiki, at <http://robocupssl.cpe.ku.ac.th/rules:main>.
Other than small grammatical and formatting tidying, I’d like to bring
your attention to the following major changes (I suggest following
along in the “Changes from 2012 to 2013” document, so you can see what
was removed as well as what was added).

In subsection 3.1.3, text is added indicating that goalie interchange
requires the referee, and from there the teams (via the refbox), to be
notified of the goalie’s pattern number (a new refbox including this
feature is almost ready for release and will use the Protobuf packet
format as discussed a while ago on this mailing list).

Subsection 3.1.4 has been removed because the rules about card handling
have been coalesced and rewritten later on.

In subsection 9.3, the phrase “other than due to a forced restart” has
been added to the double touch rules. In my opinion, it makes no sense
to apply the double touch rules to a forced restart because both teams,
and multiple robots per team, can touch the ball at the same time;
there is no specific “kicker” who should not be allowed to double
touch. The original occurrence of the phrase “neutral restart” has been
replaced by “forced restart” for clarity, as that is what it is called
in the referee box.

In subsection 9.3 further down, a line has been added making it
absolutely clear that a forced restart has only happened and teams may
only approach the ball after the referee indicates the forced restart.

In subsection 12.1, the broken robot rule has been removed (as it now
awards an indirect, not a direct, free kick; this was intended all
along but accidentally put in the wrong section). The two defenders
rule was deleted from this section and placed in subsection 12.2
regarding penalty kicks; having it here was pointless as two defenders
could never happen except inside the defense area.

In subsection 12.2, a new two defenders rule was added that now only
awards a penalty kick if the second defender and the ball are both in
the defense area at the same time, or if the second defender touches the
ball while inside the defense area (the defender might be straddling
the line of the defense area, so the second defender could touch the
ball while the ball itself is not actually in the defense area—this is
still a penalty). This objective metric should reduce confusion about
whether the second defender materially affected gameplay.

In subsection 12.3, the broken robot rule removed from 12.1 has been
inserted, and the chip goal rule has been updated. I have summarized
the new chip goal rule in a separate paragraph below, as it affects many
parts of the text.

In subsection 12.4.1, the yellow card handling rule has been rewritten.
As the rule was previously written, it would in theory have allowed a
robot to be sent off with a yellow card but then be interchanged for
some other robot immediately; of course, we never played that way,
rather taking a yellow card to decrease the number of robots allowed on
the field without affecting any specific robot. The new rule doesn’t
actually change how we play, it just updates the text to reflect
reality.

Subsection 12.4.2 makes the same update for red cards.

Decision of the Technical Committee #7 of Law 12 only applied to the
old chip goal rules, so it is deleted.

Subsection 13.2 updates the outcomes of direct free kicks for the new
chip goal rule.

Subsection 14.4 updates the outcomes of penalty kicks for the new chip
goal rule.

Law 15 indicates what happens if a throw-in is kicked directly into a
goal. The previous rules simply stated that this was not permitted,
without indicating what happened in result. This would mean that the
ruling would degenerate to the ball crossing the goal line without
scoring, which would grant a goal or corner kick to the opponent of the
last team to touch the ball. However, there is a problem with this
interpretation: throw-ins are signalled to the teams as indirect free
kicks, but actual indirect free kicks award a goal kick to the kicking
team if they get the ball directly into the goal. Therefore, with the
rules as previously written, the same signal would sometimes make a
direct kick into the goal a good thing (indirect free kick) but
sometimes a bad thing (throw-in)! The two added clauses make the
throw-in follow the same rules as the indirect free kick, thus removing
this confusion.

Subsections 16.1 and 17.1 update the outcomes of goal and corner kicks
for the new chip goal rule.

Subsection A.3 is added and explains the semantics of an abandoned
(forfeit) match.

Subsection A.4 is added and dictates that round-robin games shall end
early if the score difference between the two teams reaches ten points.

Throughout various sections, text has been updated for the new chip
goal rules. The new chip goal rules are intended to simplify the rules
and encourage more chipping. The fundamental principles of the new
rules are as follows:

(1) Chip goals are usually permitted. However, as a goalie in actual
soccer would be allowed to catch a high-flying ball with his or her
hands, so a goalie in SSL will be allowed to “catch” a ball. Of course,
the robot does not actually have any way to catch the ball. Therefore,
the chip goal rule dictates that if the ball flies above 150 mm, touches
the goalie, and then goes directly into the goal without touching any
other robot, then the goalie is considered to have caught the ball; no
goal is awarded, and instead the defending team is given an indirect
free kick. This rule only applies if the last robot to touch the ball
before the goalie is an attacker; it does not apply if the ball touches
a defender, then touches the goalie, then enters the goal.

(2) Chip goals directly from restarts of play (other than neutral
restarts, i.e. Force Start) are not permitted; they are generally
handled the same as a goal scored from an indirect free kick, but only
for the kicker’s opponent’s goal—these rules do not apply to own goals.
Specifically:
(a) A direct chip goal from a direct free kick awards the kicker a goal
kick (just like any direct goal on an indirect free kick).
(b) A direct chip goal from an indirect free kick awards the kicker a
goal kick (this is true for ANY direct goal from an indirect free kick,
so no rule is needed).
(c) A direct chip goal from a goal kick causes the goal kick to be
retaken.
(d) A direct chip goal from a corner kick awards the kicker a goal kick.

(3) Chipping shall not be used for penalty kicks. If the kicker chips
on a penalty kick and the ball rises above 150 mm before it touches the
goalie or the goal structure, the penalty kick is forfeit—no goal is
awarded if the ball goes in, and the kick is not retaken.

Please feel free to contact this list with any questions or concerns
or, for confidential matters, the Technical Committee (at
<rc-ssl-tc at lists.robocup.org>) or me personally (at <chead at chead.ca>).

Christopher Head
RoboCup Small Size League Technical Committee Chair
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