# YMTC: Per the CURRENT RULES how will FIRST score the STJB's?

Preamble:

Go here to read long thread about how we got to this point and the consequences of scoring this way or that.

Read it as background and comment on it as you see fit on that thread.

Given what you know of the rules how will FIRST score STJB’s?

STJB = the “Stack That Jack Built” a picture is shown below.

http://www.grovesrobotics.org/NoScore.jpg

Here is the post where Jack Jones posted his picture of the STJB.

So… …do your homework, think things through, and answer the following question:

Given the CURRENT RULES*, how will FIRST score STJB’s?

1. Red 2 Tetras, Blue 1 Tetra, Blue Owns the Stack
2. Red 1 Tetras, Blue 1 Tetra, Blue Owns the Stack
3. Red 0 Tetras, Blue 1 Tetra, Blue Owns the Stack
4. Red 2 Tetras, Blue 0 Tetra, Red Owns the Stack
5. Red 1 Tetras, Blue 0 Tetra, Red Owns the Stack
6. Red 0 Tetras, Blue 0 Tetra, Neither Own the Stack
7. No Idea
8. None of the above (explain)

I think I have all the combinations possible (assuming that you have to have at least one tetra score to own the stack).

Joe J.

*by this I mean how rules are currently written and interpreted at this point in time, after 5 weeks of regionals, just 1 week before the championships.

I posted a different answer; but then went and re-read the rules (section 4.3.1).

It doesn’t matter what occurred DURING the 2:15 match. It ONLY matters what the tetras look like AFTER the buzzer.

In this case, the correct answer is #6.

All three of the tetras are NOT properly “seated” (within 6" on all four apexes) on to what is called the “supporting structure” (the goal or any tetra underneath.

Although it looks like one red tetra and one blue tetra was properly seated at some point during the match; at a later point in time the 3rd tetra (2nd red) dislodged BOTH of the other tetras, therefore nullifying everything.

In the real world, a lot of stuff happens. There is no way to write rules/laws that accommodate for every permutation. I’ve seen a lot of these weird stacks at three different regionals, as well as a stack of seven that got completely toppled during the match. I expect to see a lot of on-field YMTC decisions during Nationals as well. let’s all have FUN and be gracious professionals.

Well, I’m the one Tyler refereed to in this post. So, now that the idea is out, I’ll give you my take on it.

We have played around with tetras, stacking them almost every way possible. In the STJB configuration, the was NO WAY to get all four apexes of any of the tetras within 6". Now is a good time to quote the rule.

If none of the tetras have all four (4) apexes within 6", they don’t count. So, in this case shown, no one owns the goal and no tetras count.

Tonight, I will take some pictures of oddly stacked tetras so that everyone can see how they work in real life.

In the only order that seems possible for them to be put on… it looks as if all three are within 6 inches of another tetra
BUT the 2nd red tetra is not placed on top of the first… which would void it… and also void the blue tetra… because it does not look to be within the 6 inches of the only legally capped red tetra
this is a strategical anticapping defense to me… but no probable to do…
it’s similar when you place a tetra on a goal you already own and the tetra falls to one of its previously lower vertices… and now rests in a position perpendicular to the goal tetra-- the tetra doesn’t count… but it prevents your opponents from placing a tetra on top… sorry don’t have a pic

I agree that every tetra looks to me like it has at least one apexes than 6" away from where it should be to be counted. I am willing to concede that it is so. BUT…

…the Constitution says things like "Congress shall make no law concerning… " and yet we have laws concerning…

In the end, the words in the Constitution mean what the courts SAY they mean.

So… …we have reliable sources reporting that well trained referees have ruled various ways concerning the STJB’s.

Which set of refs were right? Which court has precedence?

I am sure I don’t know. I am interested to see what others think about this case and how the rules as we know them today will apply.

Joe J.

We had the referees rule on this during a practice match at the Florida regional. The rule is that for a tetra to be stacked it’s apex must be six inches or less from the stacked tetra (or goal) below it. I leave the exact wording for the lawyer types.

In our instance both of our tetras were more than six inches from the supporting goal. Therefore, neither of them counted. It is possible, however, to get the bottom tetra within six inches of the supporting tetra (or goal) apex. The second one, usually, will not be stacked due to geometric constraints and all subsequent tetras will not count.

I’m Curie-ous to see how they rule it at the Championship.

I hate this particular situation, because it exposes an area where the rules are very, very ambiguous. (I won’t touch rulemakers’ intent for now…)

Exclusive or, or inclusive or? If exclusive, then you can’t be supported on more than one object; if inclusive, you can, as in the top red tetra illustrated.

Is this the definition of “properly seated”, or is this a necessary but insufficent part of the stacking condition? Furthermore, does “structure” refer to a single object, or collection of objects. I’d tend to say that it refers to the collection, but since a tetra or goal is itself a structure, it is ambiguous.

Again, is this a definition, or a part of a definition, or just descriptive language? It is apparent that the tetras shown are not “precariously positioned” (which would seem to require a substantial risk of collapse, over and above a regular stack), but yet, depending on the interpretation of “properly seated”, such tetras may or may not be considered stacked.

I’m not too concerned about this part, now that the “when is the tetra part of a robot” question has been cleared up. (As in, a robot-held tetra touches the stack; per <QA1852>, it’s not part of the robot at the end of the match, since the HP loading sequence has ended.)

Remember: lawyering and engineering are the same, in that in both, you’ve got to understand the definitions of the issues which you confront. Precise rules make both groups happy.

After seeing the original picture of oddly-nested tetras early in the season, I duplicated it on our practice field and showed it to some of the students on our team. After much boggling, and a little measuring, we found that the bottom tetra could be stacked properly with all four vertices within six inches of the goal structure. The next one “up” could also have all its vertices within six inches of the first tetra, but it’s obviously not stacked on top of it, so wouldn’t count.

We never considered the issue of trying to overcap the odd pair, but it’s pretty evident that the six inch criterion can’t be met.

Alan, I think I recall you guys stacked one like this against 269 Cooney quest at Boilermaker. They all counted and the highest color owned it. You guys simultaneously capped at the last few seconds of the match, they got interlocked while being placed. I might have team numbers wrong, but I saw this situation ruled that way.

I’d argue that the call at the end of that match did not follow the CURRENT RULES as specified in this YMTC thread. I don’t know what the refs’ logic was, but I don’t think they properly applied the definition of STACKED that is given in the manual.

I forgot the camera tonight, but I did do some playing.

The first thing that needs to be clarified is what to measure. After a minute or two to testing it was obvious that measurements could vary. I originally thought that the 6" measurement would be from the center of one clover to the center of another. There are however, multiple points to measure from.
ALL MEASUREMENTS REFEREED TO ARE FROM CENTER TO CENTER OF THE CLOVERS.

Second, the tetras I was using are PVC with aluminum clovers and/or steel clovers. The goals are also PVC with steel clovers. The goals start to bend in wards when 2 or more tetras are placed on them.

So, stacking 2 tetras sideways (like the STJB) was virtually impossible to get within 6". The closet we could get them was 6.5" with a lot of pushing and forcing. Typically the tetras were 7-8" for the closest tetra and 8-10" for the second. A tetra placed on top of the 2 sideways tetras wasn’t even close to scoring, typically 15-18" away from the apex of the goal.

I could not see how any of the apexes of the tetras in the STJB are with 6" of any other tetra apex. Again, the biggest factor seems to be where the measurement is taken from.
If you are measuring the two nearest points on each clover, than the lowest tetra in the STJB is 5-6.5" from the apex of the goal.

I hope this helps some. I encourage everyone to test it out yourself and take some measurements. Also, before doing this maneuver in competition, ask for clarification from the referee. They will be happy to stop the problem before it starts.

Since three of the four points of a tetra atop a goal are nowhere near a clover, I don’t believe that’s a reasonable intepretation of the rule.

The clover at the top of a goal is not the supporting structure. If you remove the clover (while still holding the goal’s tubes in place), the tetra remains supported.

I think it’s obvious that the supporting structure is the “outer” surface of the goal, where the tetra can touch and actually be supported. That’s where I think the six inch measurement should be made from.

It looks like given new rules FIRST

’s decision is Red 0 Tetras, Blue 1 Tetra, Blue Owns the Stack. That option got a zero in the poll (at the time Update 21 was released) so I guess this is a surprise decision.

It seems like FIRST

was almost directly responding to Dr. Joe’s comments on the other thread.

This was a very productive discussion, since it yielded a Team Update to make the official ruling. I don’t think this rule clarification would have been made if this had not been discussed on the Chief Delphi forums. This is another testament to the positive impact of these forums at a time when the mood of these forums has been rather negative (complaining, ref bashing, etc.)

I am extremely disappointed in this ruling , especially at this time. Since this has not occurred during the regional events, why take such evasive action now?
In avoiding a situation that they somehow overlooked - they have nullified what was a legitimate strategic maneuver, until today.
Seems kind of late to decide what is “good” and what is “bad” for the game.
I will also apologize now to any and all that I may have offended by stating my opinion.
But - I have always spoken my mind in support, as well as opposition, to the decisions made those in position to make them at FIRST. This one I am opposed to.
Isn’t solving all of the problems part of the challenge?
Why penalize those that can or have figured out a way to play the game within all of the existing rules. Granted, this maneuver would have been a game changer for sure, but why penalize thinking “out of the box”?

I sympathize with you that it is late… and slightly irresponsible because you are PLAYING the game how they asked
BUT!
NO team has used this strategy… so I don’t really understand why you are upset… of course it’s not the most logical course of action… but it isn’t hurting anybody… or giving anyone an advantage

This may be a silly question, but is a stack like this stbj actually possible? Has it ever happened? It doesn’t seem likely or even possible to me… good discussion otherwise though.

Yes, it can happen. It happened at Midwest.
We practiced it a little before the update came out.

hmmm, I was reading this thread and had decided to vote #3 (blue has 1, owns goal), and then I read updade 21. I am suprised that the rulemakers actually agree with me for once, but I liked the discussion about an anti-capping strategy.