Soccer Entry League Experiences, Questions, Ideas, Discussions

Hi everybody,

as explained in this thread the Soccer League Committee is currently trying to get an impression of what regions are doing in terms of “Entry Leagues”. I quoted the description of what we are trying to do here:

Please share your ideas, ask your questions etc. here and not in the other thread so we can post developments to the other thread for people who just want to follow it as a news feed.

Best Regards

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hi everybody,
my comments

  1. in the German competitions the motor current was limited to 2A. I found that a reasonable limitation.
  2. I would not limit the robot weight so much. Maybe 1.5 kg is a good value.
  3. Do I understand that correctly, it is also allowed to build the robot completely from self-constructed components?
    Best regards

I also cross-posted and replied to this post over to the 2023 entry draft rule discussion thread here to try and keep this thread for general discussion and the other one for specifics of the 2023 draft rules.

Best Regards

I’ll cross-post @remosgro s here to try and put everything where everybody can find it.

1- I was waiting this discussion for years, I am happy to know that the committee is trying to give a strong regulation to Soccer Entry League.

2- Is it possible to be part of the subcommittee?

3- Dimensions of the filed must be the same for all the three leagues: usually for schools it is too expensive to build two different fields and there is the need to have more space to put two tables instead of one.

4- Two motors for movements is a good limitation: I agree with @remosgro

5- During the last two entry level soccer competition in Italy they used to play 2 vs 2 because more spectacular (one time only Lego and/or Fischertechnik then also with “selfmade”). But at European championship only 1 vs 1 and only Lego and/or Fischertechnik (Hannover and Portugal). It is time to harmonize those situations.

6- 9V supply and 1.1 kg. maximum, 22 cm. diameter.

7- Color of one of the goal post: Cyan instead of Blue. It is easier to recognize in not well lit environments (happened many times).


The form to join the Subcommittee has been on the forum since April, we’re looking to get as many perspectives from as many regions as we can get on board.

We have specified flexible field sizes to enable the use of old Soccer A fields or easy (and temporary) conversion of First Lego League or regular soccer fields. The reason we can’t just use normal fields is that many schools or clubs just starting out don’t have those either and more importantly that beginners, particularly with robots built from Kits like Daisen (JP) or Lego/Fischer Technik (European regions) can’t do line detection very well (in fact a lot of 2:2 teams are struggling there) so walls are needed.

The issue with this is that it hinders reuse of 1:1 Entry LWL robots in 2:2 LWL, particularly for teams with fewer resources.

This is ultimately up to the Italian organizers, most other European regions I’m aware of are running 1:1 for Entry (Standard Kit or self-build or two Entry leagues) and for the proposed rules that’s also going to be he case.

9V we’re scrapping for the reasons outlined here, 1.1kg and 22cm are what is in the draft.

This is an interesting proposal that deserves its own discussion thread, particularly because it affects both Entry and non-entry.

Best Regards

If we only use 2 motors, this robot is no longer suitable in the LWL

Thank you for the quick answer.

1- I used Pololu motors 12V and effectively using the same series but 6V introduce more problems because high stall current. I think that put a limitation of 2A stall current is a good idea. Some students (not mine) playing Open soccer told me they have four motors of a well known German brand: every motor costs 300 euros! So a four wheels robot costs almost 1500 euros only motors (4+almost one as replacement, they told me). The problem here is that I see an apocalyptic growing of the cost of every single soccer robot. We have to try to keep the “price” low at least in the Entry category, IMO. This way a mentor can start the activities with students using a small budget and then the next year, for example, pass to LWL or Open if the students can deal or the budget grow. Any suggestion?

2- I want to form two teams, one Entry and one LWL: actually must I make two different playgrounds?

3- Manage a four wheels holonomic robot can be considered an ENTRY level? Or the Entry league is, by the moment, a sort of “a little bit less difficult” LWL (talking about the robot construction)?

4- Can we use a camera in the future Entry level? Use a camera is really “Entry”?

5- Hypothesis: this year we build a two wheels robot for Entry (possibly not expensive), next year the team change to LWL and a new team starts with Entry. After only two years I have a stable situation. I mean, depending on what mentors are planning it is not so indispensable reuse a 3 or 4 wheels configuration for Entry and LWL at the same time.

Thanks to everyone for the interesting discussion. Cheers.

The world champions in Open Soccer this year used cheap (30€ incl. controllers I think) motors and ran those at 20% power - I agree that it’s a different story for LWL though. The problem is that at 2A current limit the advantage of the 300€ doesn’t shrink, it grows. A price cap might actually be an option, I think there is a separate thread on the idea of a price cap.

A regular soccer field can be converted to a Soccer Entry field with just a couple of walls. Using the field as is is impractical because requiring line detection from beginners (particularly the Standard Kit ones) is not going to work. To be compatible with existing Equipment (the pre-2010 “Soccer A”-fields can be used, so can FLL fields when temporarily fitted with goals on two sides) we specified a large size range.

The maths for omniwheels is straight forward enough and in the Standard Kit League we see three-LEGO-Omniwheel robots a lot (with omniwheels made from Lego parts). I wouldn’t consider that too difficult. We should provide good documentation on how holonomic drive using omniwheels works.

We are trying not to require camera use because current camera modules don’t offer the reliability and ease of use that IR sensors do.

The idea of staying close to regular LWL is to enable teams to switch while keeping their robot, particularly for new teams starting out at schools/clubs without established RoboCup Junior presence is where we think this is very valuable. Schools/clubs that have some experience will easily be able to do the same - after two years in Entry you might even be looking at a situation where the Entry parts would only become available to new Students in the third year if the older team doesn’t immediately switch leagues. Passing entire robots down to new Entry teams is not intended.
It does seem to be the case that adding line sensors and making the robots stay in bounds reliably are enough of a challenge for switching over, also building a new drive system might take valuable time away from other improvements teams would like to make.


A lot of “food for thought”. Thank you.