[robocup-small] the rule of "Two defender in defence area"

Fri Nov 23 04:33:23 EST 2012

Hi all,

>From my understanding, the primary reason that the two defenders rule is
required is because the goal is so small in comparison to the robots, and
multiple defending robots could effectively block the entire goal.  The
proportions in this game seem a lot closer to hockey than soccer, so
mimicking FIFA rules might not make sense in this case.  However, it's
still important that a defending team can't unfairly block their goal with
multiple robots.  A few alternatives that come to mind are:

- Increasing the width of the goal to obtain a larger robot-to-goal ratio
and allowing multiple defenders in the defense area.  Multiple defenders in
front of the goal would be less effective, thus leaving it to the defending
team to choose their tactic.  This of course would give a greater advantage
to the offense in a penalty kick situation.

- Not allowing a second defender into the defense area until an offender
has crossed into the defense area -- a variant of an offside rule.  The
current issue of offenders "pushing" defenders into the defense area would
not be solved, but at least the offense would be initiating entrance into
the defense zone.

- One way to overcome this "pushing" problem could be a "no-contact against
defenders" rule (or more specifically, no continuous pushing against
defenders), thereby eliminating the uncertainty of whether a defender was
pushed into the defense or crossed willingly.

- This one might be difficult to implement: defenders are allowed into the
defense zone, but they cannot intercept a direct shot on net.  This would
be simulating a human "hand ball in the goal area", which would warrant a
penalty kick.  Of course, the offense could easily take advantage of this
by shooting straight at defenders in the goal area...

- One idea that might be worth implementing regardless of this rule change
is to give goalies an easily identifiable feature, such as a distinct
pattern/colour/extra dot/etc (a "goalie jersey").  This would allow the
referee to easily identify the goalie during game-play, which could make
the referee's job easier for current and future rules.

Some of these ideas are not as practical as others, but I felt I should
suggest them all regardless, as others will probably be able to improve
them or generate new ideas from them.

Regards,
Jordan Balanko

-----
UBC Thunderbots | Administrative Team
3rd Year Mechanical Engineering, Mechatronics Option
University of British Columbia
www.ubcthunderbots.ca |   <778.773.1940>778.773.1940
-----

On Thu, Nov 22, 2012 at 9:34 AM, Carlos Saith Rodriguez <
saith_rodriguez at hotmail.com> wrote:

>  Hi everyone,
>
> It is clear that the rule should not be removed, one of the problems that
> our team had in 2011 and 2012 is related to some referees that have
> different interpretations about rules or they just ignore them and we do
> not blame them, we know it's very hard  to know all rules and there are
> some rules that can have multiple interpretations.
>
> Nevertheless,  I do not think you can compare a FIFA referee with one of
> our league, because they do this every day, are very experienced.
>
> Our concern is that as all teams have worked hard to get economic
> resources and is very frustrating that everything can be truncated by poor
> refereeing decisions. We realize that there will always be but not as
> frecuently.
>
> It would be great create a guide that should be released months before the
> competitions.
>
>
> Regards
>
> Saith Rodriguez
> STOx's Team Leader
>
> ------------------------------
> From: jgurzoni at yahoo.com.br
> To: robocup-small at cc.gatech.edu
> Date: Thu, 22 Nov 2012 14:33:48 -0200
>
> Subject: Re: [robocup-small] the rule of "Two defender in defence area"
>
> Hello everybody
>
> I see the point that this rule alone is a source of disputes and a ‘fix’
> should be shought, however, I have similar concerns to those expressed by
> Andrea, particularly the difficulties for referees to see the event in a
> split second. Let’s remind also that this rule was created to avoid teams
> simply putting 3 robots in front of the goal, a similar reason why the
> defense area was increased. If we remove it, simply, we may have the
> problem it is currently preventing.
>
>
>
> I also think that we need to be aware that adding ‘precision’ to the
> rules, like defining a specific percentage of the robot in the area, tend
> not to work because humans can’t detect that with naked eye, neither is
> simple to create measurement systems to this end. Teams and referees should
> focus on the spirit of the rules, not on their millimeter precision.
>
> The referee’s power to judge an event is important and necessary, so what
> we could do (regardless if this rule actually gets modified) is to do what
> real soccer and virtually every sport does for referees: The organizing
> bodies create guidelines and recommendation to help referees to interpret
> the situations. For example, Fifa issues refereeing guidelines giving
> examples and suggestions about what level of body contact is to be allowed,
> to what level player complaints must be accepted before a yellow card,
> unsporting behavior, and so on.
>
> Amanda, Bahador and Chris started a guide like that, if I recall
> correctly.
>
>
>
>
>
>
>
> Cheers
>
> Angelo
>
>
>
>
>
> *From:* robocup-small-bounces at cc.gatech.edu [mailto:
> robocup-small-bounces at cc.gatech.edu] *On Behalf Of *Andrea Palmer
> *Sent:* Wednesday, November 21, 2012 5:09 PM
> *To:* robocup-small at cc.gatech.edu
> *Subject:* Re: [robocup-small] the rule of "Two defender in defence area"
>
>
>
> Hi all,
>
>
>
> I agree with Yonghai's statement that this rule caused difficultly in
> Mexico. However, I think so far the suggestions might make it *more* difficult
> for the referee to monitor.
>
>
>
>  If a second defender would be allowed in the area and if it would only be
> penalized if touched by the ball, then the referee must watch both the ball
> (moving at 8 m/s) and the defending robot's proximity to the defense area,
> as well as everything else he or she must be watching on the field.
>
>
>
> Although reducing referee subjectivity will help with more concrete rules
> of the game and procedures over disputes, making the rules *too* specific
> by adding the percentage of the robot that is allowed in the box adds more
> complications during the game. How easy will it be for a referee tell the
> difference between 50% and 30% of the robot over the line?  I think the
> referees need a better explanation of this rule and when to enforce it.
> Does it count if an attacking robot pushes the defending robot in the area?
> Does it count if the robot is passing through the box, but is not staying
> in the box (yes, if the ball touches that robot)?
>
>
>
> I can anticipate more arguments during competition around this issue if,
> for example, the second defender and the goalie are close to each other,
> inside the defense area, and the ball touches one of them. How is a referee
> supposed to tell which robot the ball touches?
>
>
>
> Finally, if a second defender would be allowed in the area, what would
> happen if a third crossed the defense line too? Then, not only would the
> referee have to closely watch the third robot to see if it is, in fact, in
> the defense area, but also it might require the initial rule that caused
> this discussion in the first place.
>
>
>
> Please also keep in mind that there are currently only two referees per
> game that walk along the sides of the field. During a game, there are
> usually many team members with many sets of eyes along the ends of the
> field who might have a better view of the defense area, and it is easier
> for them to catch what the referees missed.
>
>
>
> Thanks,
>
>
>
> Andrea Palmer
>
> UBC Thunderbots
>
> On Wed, Nov 21, 2012 at 10:32 AM, Carlos Saith Rodriguez <
> saith_rodriguez at hotmail.com> wrote:
>
> Hello friends
>
> I agree with Yonghai, this rule has created many inconveniences and
> clashes between the teams and that's not good for our community.
>
> The proposal is good, but it needs to be very specific. for example, in
> any situation in which the defender touches the ball inside the defense
> area was penalized.
>
> More over it is necessary to define exactly when a robot is in the defense
> area: when the robot touches the line delimiting the area or when 50% of
> the robot is inside the area.
>
> We must find a solution to decrease the subjective interpretation of the
> referee.
>
> Regards
>
> Saith Rodriguez
> STOx's Team Leader
>
>
> > Date: Wed, 21 Nov 2012 22:44:15 +0800
> > From: liunian at zju.edu.cn
> > To: robocup-small at cc.gatech.edu
> > Subject: [robocup-small] the rule of "Two defender in defence area"
>
>
> >
> > Hi everybody,
> >
> > Maybe everybody in Mexico has a very deep impression on the law
> > of "Two defender in defence area". There were 3 penalties in the
> > Quarterfinals Skuba vs Immortals due to this law.
> > Law 12 of rule 2012 give the detial definition: is the second
> > defending robot to simultaneously occupy the team's defence area in
> > such a way tosubstantially affect game play. But the rule did not
> > give a clear definition of "substantially affect game play", is all up
> > to the referee. So the problem is comming, i remembered that maybe
> > more than 50% argument during the game are related to this law.
> > In real soccer game, there has not limitaion of the number of
> > defenders in defence area, but only allow the Goal keeper can handle
> > the ball, if the other player touch the ball with hand, he will
> > receive a read card and the team will receive a penalty.
> > We can learn from this real soccer rule. All the robot can enter
> > it's own defence area, but only the goal keeper can touch the ball, if
> > the other robot touch the ball, the team will receive a read card and
> > a penalty.
> >
> > Best regards.
> >
> > Yonghai Wu
> > _______________________________________________
> > robocup-small mailing list
> > robocup-small at cc.gatech.edu
> > https://mailman.cc.gatech.edu/mailman/listinfo/robocup-small
>
>
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