<div dir="ltr">Dear SSL-Community and Committee members,<br><br>We would like to start this message by thanking you for consulting the community on the proposed rule changes and that we are saddened by the sudden resignation of our beloved OC members. Like the teams that gave their feedback before us, we are concerned about the amount and impact of the rule changes this late in the year. We evaluated the proposed changes disregarding the difficulties that may occur in the implementation of our software, to increase the quality of the SSL.<br><br><b>Number of robots + field size</b><br>We agree with the increase of robots from 8 to 11, as was determined in the open TC/OC meeting. Like ER-Force, we do not think that this increment is feasible without increasing the field size. The reasoning is that the current field size causes the same area per robot as in Division B. While this argumentation seems reasonable, there are some problems. The type of gameplay differs (greatly) between the two divisions. In Division A, the gameplay is more dynamic and defence is a primary focus. Maintaining the current field size could cause more crashes or decrease the speed of gameplay in Division A, slowing down the games. Furthermore, as ER-Force pointed out in their email, it is possible to cover the entire goal line using 11 robots. <br><br>We propose that in order to work with 11 robots, the field size should also be increased. If the financial resources to increase the field size are not available, we should work with 8 robots in Bordeaux.<br><br><b>Introducing walls into a subset of games (DivA only)</b><br>While we understand the motivation behind adding walls to the games, we do not support the initiative. We think it is a treatment for the symptom, when the underlying problem is that we simply need to get better at keeping the ball in the field. By introducing handicaps like walls, we are suddenly playing an entirely different game. This diverges from the original goal of the robocup, where the SSL was meant to focus on creating the top-level strategies, which can then be translated to the middle size and humanoid league, to eventually accomplish the goal of creating a humanoid soccer team. <br><br>More specifically, adding walls to the field opens up multiple new strategies and tactics that all do not work for real soccer. Therefore, we essentially produce research that cannot easily be applied to the other leagues.<br><br>Finally, should the TC/OC still consider it necessary to add walls, we would propose they only be placed at the sides of the field, and not at the goal lines. Taking a shot at goal should be risky: in real soccer, if you take a shot at goal and miss, you lose your ball possession and have to start your attack all over again. However, with the currently proposed changes, as long as you are fast enough, you can send a lot of robots close to the goal, and they will just reflex-kick continuously in the direction of the defending goal, until the defending team can chip/clear the ball to the other side of the field. Such a scenario is more of a shooting gallery than a soccer match.<br><br><b>Merge indirect and direct free kick into direct free kick (both Div)</b><br>The difference between an indirect and direct free kick is difficult to detect for the autoRef as well as the human referee. This casued several arguments during the matches and until we can properly detect when a free kick should be direct or indirect, we agree that both should be merged into direct free kick. We do believe that the autoRef should be improved to properly detect the difference, since direct and indirect free kicks are used in human soccer games which means we have to be able to work with them some day. <br><br><b>Remove the double touch foul (both Div)</b><br>We agree with the removal of double touch, since this will encourage the teams to experiment with dribbling by small kicks. We do however wish that the double touch foul remains valid during penalties (if they are not removed) since this allows for unfair gameplay (and is also not allowed in real soccer).<br><br><b>Robot interchange during game play (DivA only) + Do not stop game for yellow cards (both Div)<br></b>The way we understand the current changes, we are afraid that it might get unsafe for the person that has to interchange the robots. Also, with the cards not bound to individual robots, the software does not know which robot the team wants to take out of the field. If this was known, the robot could drive to a position on the field where it can be safely removed. The way we understand it, someone has to now remove a moving robot from the field. Furthermore, the outfit of an individual could mess with the vision and the individual can be detected as a ball. <br><br>As a final note we would like to see a clear goal for the SSL. With the proposed changes we are getting further and further away from an actual soccer game, which is the current goal, and working towards a game which is 'fun to look at'.<div><br></div><div>On behalf of RoboTeam Twente,<br><br><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div style="color:rgb(136,136,136);font-size:12.8px"><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px">Met vriendelijke groet / Kind regards,</span><i style="color:rgb(0,0,0);font-size:12px"><br></i></div><div style="color:rgb(136,136,136);font-size:12.8px"><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px"><br></span></div><div style="color:rgb(136,136,136);font-size:12.8px"><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px">Selina Zwerver</span></div><div style="color:rgb(136,136,136);font-size:12.8px"><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px"><br></span></div><div style="color:rgb(136,136,136);font-size:12.8px"><span style="color:rgb(0,0,0);font-family:Helvetica;font-size:12px"><i>Finance & Logistics Manager</i></span></div><div><font color="#000000" face="Helvetica"><span style="font-size:12px"><i>RoboTeam Twente | University of Twente</i></span></font></div><div><font color="#000000" face="Helvetica"><span style="font-size:12px"><br></span></font></div><div><font size="1" color="#000000">Mobiel: +31 618 70 2636</font></div><div><font size="1" color="#000000">Internet: <a href="https://roboteamtwente.nl/" style="color:rgb(17,85,204)" target="_blank">RoboTeam Twente</a></font></div><div><font size="1" color="#000000">LinkedIn: <a href="https://www.linkedin.com/in/selina-zwerver-5462bb129/" style="color:rgb(17,85,204)" target="_blank">Selina Zwerver</a></font></div><div><br></div><div><img src="https://docs.google.com/uc?export=download&id=1IHqwxVbp654EbwFZ8kK8MIKNKvrxOwgf&revid=0B0tUlcGsNq3Zdlo2c0hEeHcrWGphWGllRWJNM2JPdnUrS2I0PQ" width="200" height="75"></div></div></div></div></div></div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, 25 Nov 2019 at 18:34, Lukas Wegmann <<a href="mailto:lukas.wegmann@robotics-erlangen.de">lukas.wegmann@robotics-erlangen.de</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<p>Dear SSL-Community and Committee members,<br>
<br>
first of all we would like to thank you for being open about the
upcoming rule proposals and enabling feedback.<br>
That being said, we have various concerns and comments regarding
them. <br>
<br>
We wish to preface this by saying that, while we appreciate
striving to improve the SSL as a whole, the proposed changes are
numerous, sudden and time intensive to implement. The consequence
will be that less time can be spent on developing actual AI
improvements that would contribute to meaningful research. This is
reinforced by the fact that many if not most of the changes are
completely unexpected and some even directly contradict decisions
made in the open TC/OC meeting of the previous RoboCup, which we
find especially unacceptable.<br>
<br>
Nonetheless we wish to provide constructive feedback on the
proposals with the intent of contributing to make the SSL as best
as it can be.</p>
<p><br>
</p>
<u><b>Number of robots increased to 11 (DivA only)</b></u><br>
This change was already agreed upon during the open TC/OC meeting
and we think that it will improve gameplay and make further research
necessary.<br>
However, without the increase of the field size, it is not clear if
this change has the desired effects. The argument that there will
still be more space per robot than in Division B is lacking as no
one said that Division B has the optimal state. Especially since the
defense of Division A teams tends to be better than most Division B
teams, even fewer goals could be shot out of regular game play.<br>
<br>
This fact can be shown by the image in the attachment, showing 11
robots acting as defenders. Although there is some space between the
robots, they can essentially cover the whole front side of the
defense area, which would make it very hard to score goals against a
defensive team.<br>
<br>
Furthermore, we believe the statement that an increased field size
would not have any significant effect on ball outs to be vastly
incorrect. This years final game serves as a fine example of this,
when the ball did not leave the field for minutes at a time, leading
to the referee having to manually end the match over a minute after
the official game time was over. While this is in general dependent
on the teams in question, the possibility of keeping the ball in
play longer should serve as an incentive for improving ball control
and we think that keeping the field size as it is would mitigate
that.<br>
Introducing walls into a subset of games (DivA only)<br>
While in general we are not opposed to introducing walls to the SSL
league, we find it quite late in the year to implement such a
radical change. This would necessitate major changes in our software
to properly use the new options in the offense as well as to
properly defend against an attacker using such a strategy. We would
prefer to have such radical changes discussed in person at the
RoboCup instead of them suddenly being announced via email.<br>
<br>
<u><b>Reduce stoppages due to fouls (both Div)</b></u><br>
The proposed changes on how to handle fouls seem inconsistent. First
of all, some offenses are explicitly marked to increase the foul
counter while some others are not. Continuing the game after
excessive dribbling while still counting goals shot after the fact
allows teams to gain a huge advantage in exchange for a relatively
minor punishment. Giving Force Start instead of a Freekick for some
fouls, e.g. Kick Timeout or Defender too close to Ball, without
increasing the foul counter effectively removes these rules. Also,
"the percentage of game-states" does not necessary correlate with
"spent time on solving the problem" as stated in the long term
goals. We rarely focus our development time on non-game-states, as
we cannot score during those. While it still might be an interesting
metric for OC and viewers, it does not reflect the time spent to
solve a particular problem, and therefore should not be overvalued
by rule changes. For further comments, see the Google Document.<br>
<br>
<p><u><b>Add a cost to timeouts (DivA only)</b></u></p>
While we can agree that reducing stoppage time of any kind, we have
several issues with this rule change in particular.<br>
First of all we believe that inventing arbitrary and unrelated game
punishments to discourage a certain team behavior is lackluster at
best. So far there is not a single case where a certain team
behaviour (except for severe unsporting behavior) has any effect on
the game state and we think it should stay that way. Freekicks and
fouls are designed for the AI and robots, not their creators. There
are plenty of other ways to discourage or reduce timeouts and since
many of the following rule changes can already cost timeouts, we
believe that no further punishment is necessary.<br>
<br>
<p><u><b>Remove Penalty Kicks (both Div)</b></u></p>
While we found the number of penalty kicks during the RoboCup
unreasonable (even given that we won most of our games due to
penalty kicks), the proposed change to drop them entirely might
result in adverse effects. For one, this punishes Division B teams
far more than Division A teams. When having 11 robots, losing one,
two or even three is not such a hard punishment, while when the game
is played with only 6 robots, losing three is catastrophic.
Punishing Division B teams more for fouls is not reasonable as
higher standards regarding fouls should be applied to Division A
teams instead.<br>
<p> Additionally, in case a Division A team does not have 11 robots
(which will most likely happen for some teams next year) or the
game has only a few minutes left, red and yellow cards mostly lose
their significance. Therefore, red cards may not present a
sufficient punishment in Division A.</p>
<br>
<u><b>Vision dropouts (both Div)</b></u><br>
While it is possible to navigate the own robots even with severely
degraded vision information, nothing can be done about the opponent
robots or the ball. Losing too much vision information about the
opponent will result in additional collisions and other fouls. In
addition, the autoref will not be able to properly judge the
situation without the required level of vision fidelity.<br>
Having the teams make sure the vision is good enough before the game
will not solve this problem as games are often played directly one
after the other, leaving no time for vision adjustments in between.<br>
Offering incentives to improve the SSL vision software might solve
the underlying problem in a more efficient and sustainable manner.<br>
<br>
<u><b><br>
</b></u><u><b> Final thoughts</b></u><br>
Many of the proposed changes are just too much and too late after
the RoboCup. Such big rule changes should be discussed after the
RoboCup during the open TC/OC meeting and the conclusions reached
there should at least roughly be honored.<br>
While many of the changes would surely succeed in bringing the
non-game time during games down to a minimum, they do not present
significant incentive or reason for more research in our league and
might even hinder it due to the time drain of additional
implementation work. Building robots is a slow, exhaustive and
expensive process. A lot of teams rely on the fact that their robots
can be used for some time until the financial and human resources
recover.<br>
<br>
This fact does lead me to wonder weather "big changes with rapid
adoption" are good for the league. It could lead to cheaper robots
with shorter lifetime, decreasing the overall performance of the
league and risking our position as the "most interesting league to
watch on the Robocup"<br>
<br>
Therefore, we hope that the changes are reconsidered and properly
discussed in Bordeaux after the RoboCup.<br>
<br>
Unrelated to the rule changes, we still miss a proper response and
clarification regarding the recent events like the Thunderbots have
already asked for. The resignation of two cherished OC members is
unprecedented and the email exchange leading up to this raises
numerous concerns about the way business is conducted. We
wholeheartedly back the call for information that Thunderbots
initiated. We are in desperate need of more transparency.<br>
<p><br>
</p>
With best regards<br>
<p> ER-Force</p>
<div>On 20.11.19 06:51, Carla Cosenza wrote:<br>
</div>
<blockquote type="cite">
<div>
<b>
<p dir="ltr"><span>Dear SSL Community,</span></p>
<br>
<p dir="ltr"><span>We have been striving for a long time to
increase actual soccer game-on time during SSL games.
Unfortunately, despite several rules iterations, our
analysis over the game logs from RoboCup 2018 and 2019
show that we are still far off the mark - games had an
average of only 20% actual game-on time during RoboCup
2018, and 15% actual game on time during RoboCup 2019. To
make the situation worse, we have far more special game
states than game on.</span></p>
<br>
<p dir="ltr"><span>All the recent events have been caused by
the lack of established procedure for making big changes
with rapid adoption for the Small Size League. We were
trying to decrease the amount of time not spent on actual
soccer during matches and did not manage to come to an
agreement. In order to prevent this, we are creating a
method for these decisions. Due to its importance, it will
be discussed in Bordeaux with representation of all teams
and committees.</span></p>
<br>
<p dir="ltr"><span>For RoboCup 2020, we have created a
proposal for rule changes:
</span><a href="https://docs.google.com/document/d/1EBfKZfXEYq2SpcLzUb7OE68vlUKjJnk_tnaulR5CMO8" target="_blank"><span>https://docs.google.com/document/d/1EBfKZfXEYq2SpcLzUb7OE68vlUKjJnk_tnaulR5CMO8</span></a></p>
<p dir="ltr"><span>You can also find an immutable copy of the
document attached to this mail. We encourage teams to give
us feedback by the end of November. You can use the
comment and suggestion mode or reply to this mail.</span></p>
<p dir="ltr"><span>If there is well justified concern, we’ll
consider it when finalizing the rule changes. Some of the
most notable changes are:</span></p>
<br>
<p dir="ltr"><span>Walls for field boundaries in some Div A
matches</span></p>
<p dir="ltr"><span>In order to verify the possibility of
removing the out of bounds part of the field, we are going
to test, in some division A matches, having walls on the
boundaries of the field. This will result in having less
game states and less time spent placing the ball after it
leaves the field. Each team will be required to play at
least one game with the walls during the group stage and
before the match starts, both teams need to opt out of the
walls in order not to use them. The objective of this
change is to reduce the amount of time spent not playing
soccer during the matches. Our statistical analysis has
shown that games had an average of only 20% actual game-on
time during RoboCup 2018, and 15% actual game on time
during RoboCup 2019.</span></p>
<br>
<p dir="ltr"><span>11 robots and field size for Div A</span></p>
<p dir="ltr"><span>Having Div A reach 11 robots has been on
the SSL roadmap for this year and it will happen. Div A
teams will be allowed to have up to 11 robots on field.
The only difference is that there will not be an increase
in field size. We have measured that even if we do not
change the field size, taking Div A to 11 robots will
provide a bigger area per robot value (4.9m²) than the
current configuration for Div B does (4.5m²).</span></p>
<br>
<p dir="ltr"><span>Match Statistics</span></p>
<p dir="ltr"><span>When discussing rule changes, we need some
facts and numbers from past RoboCups to support or reject
arguments. We also need to evaluate the effects of changes
that were made. That’s why we started to establish a
standard statistics database. The SSL committee commits on
updating and evaluating these statistics each year.</span></p>
<p dir="ltr"><span>The code can be found here:
</span><a href="https://github.com/RoboCup-SSL/ssl-match-stats" target="_blank"><span>https://github.com/RoboCup-SSL/ssl-match-stats</span></a></p>
<p dir="ltr"><span>We will prepare an area on the SSL website
with more information on this soon.</span></p>
<br>
<p dir="ltr"><span>Qualification requirements</span></p>
<p dir="ltr"><span>We will update the specifications for the
qualification videos for Div A. Team have to demonstrate
passing (with a more precise definition) and ball
placement. Both can still be demonstrated by game play
footage, but we will limit the duration of the video for
both divisions. This is to encourage teams to work on
smooth game play. Details will be included in the
</span><a href="https://ssl.robocup.org/robocup-2020-qualification/" target="_blank"><span>qualification webpage</span></a><span>.</span></p>
<br>
<p dir="ltr"><span>Technical challenges</span></p>
<p dir="ltr"><span>We will repeat a version of the SSL-Vision
Blackout Challenge. Both divisions are eligible to
participate. We will also have a Ball Placement Challenge
for Div B teams only. </span><span>All Div B teams will
be required to participate in the Ball Placement
Challenge.</span><span> The intention is to prepare Div B
teams to move to Div A. More information about these
challenges will be announced later. The current
work-in-progress status can be found on GitHub:
</span><a href="https://github.com/RoboCup-SSL/technical-challenge-rules" target="_blank"><span>https://github.com/RoboCup-SSL/technical-challenge-rules</span></a><span>. </span></p>
<br>
<p dir="ltr"><span>Other reminders and updates</span></p>
<ul>
<li dir="ltr">
<p dir="ltr"><span>As stated in the previous email, all
teams will be required to bring posters in order to
present their changes and improvements to the other
teams. Like last year we will schedule a poster
session where team members can present and discuss
poster contents.</span></p>
</li>
<li dir="ltr">
<p dir="ltr"><span>We are still testing April Tags for SSL
Vision. Initial implementation works correctly but
more testing is needed. We do not anticipate forcing
teams to use the April tags at this competition.
However teams should start preparing for tags other
than the currently butterfly patterns. </span></p>
</li>
</ul>
<br>
<p dir="ltr"><span>All of these changes were based on the long
term goals of the Small Size League. The main intended
effect is to: </span></p>
<p dir="ltr">
<span>Spend more time
</span><span>solving the game-on regular soccer problem</span><span>,
not on non-soccer behaviors.</span><span> </span></p>
<p dir="ltr"><span>In particular, we anticipate ball handling
(stealing, possession, dribbling, passing) to be more
important now. We are also trying to propose challenges to
help Div B teams reach Div A, since Div B is intended to
simplify the entrance of a new team to the league.</span></p>
<br>
<p dir="ltr"><span>Team Leader Online Meeting</span></p>
<p dir="ltr"><span>We would also like to invite the team
leaders for an online meeting in order to clarify any
concerns and discuss the decisions for RoboCup 2020. We
ask each team to fill out this form (</span><a href="https://docs.google.com/forms/d/e/1FAIpQLScXR8BGCPYzZVHh0YUw8S75rYmV5HmCZk6xdenIvRXbV5yhbQ/viewform?usp=sf_link" target="_blank"><span>https://docs.google.com/forms/d/e/1FAIpQLScXR8BGCPYzZVHh0YUw8S75rYmV5HmCZk6xdenIvRXbV5yhbQ/viewform?usp=sf_link</span></a><span>)
with the name and email of their team leader so we can
send out the invite for the meeting. </span></p>
<br>
<p dir="ltr"><span>We look forward to hearing from you!</span></p>
<br>
<p dir="ltr"><span>Thank you!</span></p>
<br>
<p dir="ltr"><span>The Technical, Organization, and Executive
Committees of the Small Size League</span></p>
</b></div>
<br>
<fieldset></fieldset>
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</pre>
</blockquote>
<div>-- <br>
<div>Lukas Wegmann</div>
<div>Vorstand / Chairman</div>
<div>Robotics Erlangen e. V. </div>
<div><a>lukas.wegmann@robotics-erlangen.de</a></div>
<div><a>http://www.robotics-erlangen.de</a></div>
</div>
</div>
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