Everything there is to know about SG8

OK guys here is, in short, everything there is to know about the rule SG8, ready?

The rule as of 11-05-13

The Possessing Definition

Some Q&A

Mmmkay, to me this seems like a pretty straightforward rule, but the forums have been bombarded with Q&A’s regarding this question so let’s look at (most) of those:

Q. I would like to know if momentary possession of 4 Buckyballs would be legal. In this case lets say less than 1 second. In this case it would not affect the match score and would encourage teams to use color sensors in autonomous mode.
A. No, this is not legal. This is clearly intentional possession of more than 3 BuckyBalls.

Q. Suppose that a robot is carrying 3 buckyballs to the corner under the hanging bar, where there are a number of other buckyballs on the ground already. Is it considered possession if the robot attempts to place its 3 buckyballs into the very corner and in doing so, the ground buckyballs are also pushed in the direction of the corner?
A. This would be legal. The Robot is expelling BuckyBalls, not actively trying to control them.

Q. The robot remains in place after [herding more than three Buckyballs] in the corner [of the field] under the hanging bar and does not move. Is [this] considered possession?
A. Depending on the specific situation, this could be considered intentionally trapping BuckyBalls, thus a form of possession.

Q. If there are [more than three] buckyballs already loosely packed in [the corner of the field] and the robot moves to block the corner, but does not press up against them (although it may touch a few in maneuvering to the corner)?
A. Depending on the specific situation, this could be considered intentionally trapping BuckyBalls, thus a form of possession.

Q. [What if my robot] moves to the corner and presses them up against the field walls (trapping [more than three Buckyballs]) but [it is] in the process of hanging?
A. This is unintentional, and not what the rule is trying to prevent. This would most likely be legal, depending on the specific situation.

Q. If a blue robot places 3 blue BuckyBalls on a red robot, such that the red robot cannot remove these BuckyBalls from itself without a large amount of effort, do these BuckyBalls count towards the limit of 3 total? (I’m asking this assuming that the blue robot did not violate any other rules in the process)?
A. Please see the updated version <SG8> in the 05/10/13 version of the VEX Toss Up Game Manual. …] The Blue Robot would be disqualified, and the additional BuckyBalls would not count towards the 3 BuckyBall limit.

Q. Consider two opposing robots, each carrying three BuckyBalls. If one of these robots pushes the other, and thus its BuckyBalls, to a desired location, it is indirectly herding its opponent’s scoring objects per the provided definition of possession. Thus, one could say that the first robot is illegally in possession of six BuckyBalls – the three it directly controls and the three it inside its adversary. Is this a correct interpretation?
A. No, this is not a correct interpretation. The maneuver you described does not violate any rules.

Q. If a BuckyBall accidentally falls on a robot and the robot is unable to get rid of it, will that BuckyBall be included in the count of the number of possessed BuckyBalls? It was not “illegally placed” so I’m inclined to think it would be counted, though I feel the opposite would be most fair.
A. Any BuckyBall which accidentally lands on a Robot will count as being possessed. However, referees will be instructed to allow for a short grace period to allow Robotss to promptly remove any BuckyBalls which have landed on them.

Q. If a RED robot has a BLUE ball dropped on it, and the RED robot is unable to remove the BLUE bucky ball, is that BLUE ball counted as 1 of the 3 the RED robot can control?
A. There is no mention of the colour of the BuckyBall in this rule, thus it is irrelevant what colours the BuckyBalls are, if you Possess three or more of any combination of colours, you will be in violation of this rule.

Q. If I were to attempt to secore Bucky Balls from the stashed colum, would my robot be considered possesing more than three Bucky Balls at a time and therefore be DQ’ed if A) it were pulling out more than 3 bucky balls at a time B) already possed a bucky ball and was pulling 3+ out?
A. In both cases you would be possessing more than three BuckyBalls, thus you would be in violation of <SG8>.

Q. Are teams expected to choose paths for their robot that don’t involve driving through buckyballs?
A. In general, no.

Q. [My robot, in autonomous, takes a path that will interact with buckyballs, blah blah blah…]
A. The Possession rule is written to prevent teams from intentionally controlling more than 3 BuckyBalls at once. In the Autonomous Period, a robot that is holding two BuckyBalls and then drives directly at 3 more that are in a known location, in an attempt to move them, is clearly intentionally attempting to control more than 3 BuckyBalls at once. During the Driver Control Period things become much murkier. Instead of having the referees try and constantly evaluate intent, we’ve gone with a much more lenient interpretation of <SG8>; teams are allowed to drive through BuckyBalls provided the BuckyBalls do not move with the Robot. This way the referees aren’t trying to evaluate if every interaction with a BuckyBall is intentional, and teams who are carrying three BuckyBalls don’t need to dodge and avoid all other BuckyBalls on the field.

An unofficial but sensible conclusion

It is clear to me that this rule has been one of those “but Karthik what if x, y, z or w” kind of circumstances which sort of annoys me only because of just how clear the rule is. Going back to just the original definition of the rule, it is clear that bumping a 4th Buckyball might get you a warning, but doing something that will affect the match score might get you DQ’d.

But then comes the “ideas” on essentially how to screw someone with the specifics of this rule, like the idea of dropping playing objects on another robot. It’s illegal, not based on Karthik’s ruling but based on…

You get three Buckyballs, don’t intentionally possess a 4th or bad things may happen. It’s not complicated.

Anyone who wants to further expand on this (in a constructive, clear and concise way) may do so below. -Cody

The rule is not clear and is very hard to be followed consistently by teams and referees.

I think the rule is very clear, especially with a the Q&A that’s been going on. Cody summed up the rule very nicely:

I think the confusion is that the rule is applied differently during autonomous or driver control.

It was ruled illegal to drive through buckyballs during autonomous, even though the above suggests it should be ok.

I think some of your Q&A below would be reversed in auton mode. For example,

Q. Are teams expected to choose paths for their robot that don’t involve driving through buckyballs?
A. In general, no.

from yesterday.

So the answer in autonomous could be Yes.

I understand the spirit of the rule, I just wonder if it shouldn’t apply during autonomous to simplify things for the refs if nothing else.

It sort of frustrates me that you call the rule “clear” while most of your unnoficial answers have a “depending on the situation”, “most likely”, or “in general” in it…

The possession and herding rules are definitely not clear enough. This is shown by the countless SG8 Q&As. Several contentious possession situations came up at the very first New Zealand scrimmage this year where both refs AND competitors weren’t sure how the situation should be ruled simply because the rule AS WRITTEN does not give sufficient information about how rulings should be made.

Even the “Illegal in autonomous, legal in driver control” ruling (which is definitely not a logical ruling I would reach while interpreting the intent of the rule) is still difficult to understand. Does this mean a team can INTENTIONALLY make these movements in driver control legally? If not, how does one draw the line between intentional and accidental? I don’t think “The referees discretion” should suffice for such a major ruling, but maybe we’ll just have to deal with it? Will a team “accidentally” carrying out one of these manoeuvres decide Finals Game 3 at the World Championship this year? I wouldn’t be a bit surprised.

If a team goes out of their way to maneuver more than three buckyballs, or is clearly (and intentionally) moving buckyballs - as in they have three buckyballs in their scoring mechanism and, for example, they drive over the bump where the buckyballs are resting on top of the bump which causes those buckyballs to be knocked off the bump, then that is intentional possession. My interpretation of the rules as thus far for autonomous is that if a robot were to be placed on a field with no other robots, (i.e. a skills field), at no time should it be moving more than three buckyballs, regardless of circumstance. A team knows exactly where each buckyball is during autonomous under those conditions. If, during a match, another robot during autonomous moves buckyballs into another robot’s path, then there is no way for the soon-to-be “offending” robot to know that those buckyballs are there, and is therefore, unintentional possession and should not be punished for this circumstance.

Not according to the game manual.

The rule says herding is “intentionally pushing or impelling BuckyBall(s) to a desired location or path”, just driving through buckyballs does not determine their final location or path. The rule even says that driving through them as you describe is not herding and therefore not possession.

Again, I understand the spirit of the rule, we don’t want robots holding all the game objects, but I find it’s very ambiguous when it comes to determining whether the ball you just hit went on your intended path to your intended location.

Some more thoughts. I don’t see how these two statements can really co-exist.

Every robot wants buckyballs of their own color to be moved to a scored location and buckyballs of the opponents color to be moved to the hanging zone. Anytime you drive through the balls your intention will be to do this. You will always try and impel the ball into the more favorable position, I don’t see how you can drive through balls of your own color if moving towards the goal zone and not increase their value. It seems unlikely you would drive through the opponents buckyballs and intentionally score them.

I don’t think it’s quite as simple as Cody makes it out to be. Not for autonomous anyway. We’re using the IMEs to control the robot’s moves and sometimes, the turns go off by a few degrees as it’s trying to collect balls against the wall. It works 9 out of 10 times. But if it goes off in the course of a game, the referees can’t determine if it was intentional or not. Along the same line, if a robot is programmed to push the large ball (per the illustrated example in the other thread) but the ball happens to move out of the way, would there be a warning or disqualification when the robot runs straight into the buckyballs on the bump while carrying three?

In my team’s situation – It was not our intent to control more than three buckyballs. In fact, my students went out of their way to reprogram the routine so it would avoid other balls. They also removed the preload. But the referee couldn’t see our intent and only saw the result of the action on the field and disqualified us. So at this point, I’m still wondering whether I should advise my students to disable their autonomous routine for the hanging zone. The risk of a DQ greatly outweighs the benefit of the autonomous bonus.

Personally I don’t think the situation you described should have resulted in a disqualification. Did you explain the intent of the autonomous routine to the referee? I think this would’ve helped your case a lot, although I understand not all referees are as approachable as the great volunteers we have in New Zealand. If I were you I would encourage your students to keep trying a hanging zone autonomous routine :).

I’d say that anything you do during autonomous that involves moving buckyballs is completely intentional, under the circumstances above (if it the buckyball is there at the start of the match, not moved into a robot’s path by another robot). Therefore,if it’s intentional, you’d be moving buckyballs to a desired location.

I was one of two Head Referees at this event. While I did not referee this match, I would like to say that as Head Refs, we painstakingly went through the rules and Q&A and made calls based upon the Q&A responses up until that point. We anxiously awaited a response to 359A’s Q&A question (even informing their coach to contact Karthik directly to get a ruling), but none came in time for the event, so we had to go with what was posted up until that point.

Everyone who graciously agrees to volunteer should be commended for taking on a task that they do not have to do. Without great volunteers worldwide, none of these events would be possible.

In some matches, coaches understood that referees did not have any desire to make disqualifications and would ask my referee crew if things were okay before proceeding with their next step. We were happy to give them that feedback.

Agreed. Referees have no desire to DQ any team, but good referees want to be consistent in their rulings that are also consistent with the rules and Q&A clarifications at that point in time. I am happy that this clarification today will free up teams to attempt autonomous modes with a reduced threat of disqualification.

If the rule is clear, why are there so many Q & A?

I understand. Everything we do in autonomous is intentional, however, we had 5000 lines of code on the programming skills robot last year and it only did exactly what we intended about 20% of the time (and almost never during a real skills run :frowning: ) Yet, the drivers are so skilled that the robot does what they intend all the time, but that can be accidental ! Doesn’t make sense to me and discourages anything but “safe” autonomous code.

Lets look at the rule again and see if a different wording would make things easier and yet still acheive the same underlying goal.

No problem here, you can carry or hold on the robot a maximum of three buckyballs.

No problem here as well, don’t push the buckyballs into the field perimeter and trap them there.

So we are back to herding, this is the problematic area.

One definition of herding is as follows.

*To gather, keep, or drive (animals) in a herd.

This implies that moving objects in a group would be herding whereas hitting or momentarily pushing would not. An analogy in soccer might be the difference between running up to the ball and kicking it vs dribbling it down the field.

To actually herd the buckyballs with a robot would take a design that probably contacts the balls on more than one side. A U or V shaped frame that could contain the balls and allow intentional moving to another area. A robot with a single surface on the side pushing the buckyball will move the ball forward but will probably not be able to easily move it to an intended destination. So I would propose that the rule may perhaps have been better worded as follows.

Thoughts ?

Karthik said, “During the Autonomous Period, it is illegal to drive through a group of 3 BuckyBalls in a known position on the field, while already in possession of a BuckyBall.”

It’s not like you can’t drive through Buckyballs at all during auton. All this does is kill the autonomous strategy where you gain a few points by pushing some game elements over the bump while in possession of game objects, which is neither complicated, nor hard to understand.

No, the rule is decently clear. It’s when people ride the line that things get complex, which happens in many many many many places in the world - one of those places is programming. We call these “strange” on the line phenomena edge cases and they show up all the freaking time.

For example, dropping playing elements on an opposing robot? Yeah… that’s an edge case. One that took special attention to solve. One that no one in their right mind while drafting that rule thought of or even should have thought of.

Once again, the autonomous rule only states that you cannot plow game elements in known positions if you have another element in your possession.


And this is where things get strange. See this simple rule breaks down into a judgement. Did you program your robot to do that, or was that an accident?

But that’s not something the rule must define. A ref is should be more than capable of making a judgement here. I kind of wish the special case for autonomous gets recalled, I think it causes some confusion here.

If I were a ref today and this happened in a match, I would ignore the autonomous ruling and make a judgement call. And being a ref, tough crap - they have to accept my ruling completely valid or not.

But the reality is, if I were you right now I would write code to ensure this didn’t happen. Given the random nature of what can go wrong in auton, I’d say this is a semi-bad ruling on Karthiks part. I hope they change their mind. But in short, thow should not be herding while in possession - even in auton.

As for this match DQ’ing stuff. No ref ever should DQ under a ruling that is if-y. If it is not fully understood, could go both ways or just outright feels wrong, DO NOT DQ! A ref is a ref to make judgements and if it feels wrong and isn’t black and white - it’s time to use that there brain and make a judgement call either that or fetch the head ref (which we know didn’t happen during that match).

I still say the rule is simple and clear and so is it’s intent. What I will give the people here is that some of the rulings have been strange and that there are some nasty edge cases. That being said, I made this thread to clear things up by consolidating what we do know and what has been ruled on.

We may be able to get the less-than-crystal-clear parts of this polished if we work to identify them, Q&A them, and get rulings. Then we can consolidate that information here in a clean way so that others don’t have to scrape through hundreds of Q&A’s to get an answer to a simple question.

There are six buckyballs on the edge of the hanging zone, driving into these probably means you are possessing all six of them whether you are already holding one or not.

That’s not what it says. You can plow two buckyballs if you are in possession of one. Get that wrong by 2 inches and you can potentially be DQed. The rule also specifically says “herding”, plowing into balls and sending them who knows where is not herding in my book.

This is the point I’m trying to make, but slightly more generic. I completely agree with cody regarding SG8

I think we’re at a miscommunication here. I would agree that if an autonomous were to accidently run those buckyballs on the bump over, by barely (and by apparent accidental chance) tapping them, causing them to fall over. However, if a robot consistently and/or abuses the leniency, then a DQ or appropriate reprimands aren’t in order. In those situations, it’s a judgement call.

Assuming I understand all the rules correctly the only defense in this case is that the ref is expected to notice how an autonomous usually runs and not punish a mistake.

I am a big fan of stated rules as to avoid regional differences.

Obviously Karthik can’t define perfectly what would be considered accidental but I would appreciate if the GDC either made the rule more strict or made it more lenient just to make an understandable system.

Don’t exert force on more than 3 buckies(that you reasonably knew were there) at once ever or its DQ.
Only 3 balls may be “dribbled” at a time but striking another ball in a general direction is legal.

My problem is that the rule uses specific language. It does not say possession is “pushing”, “tapping” or “driving into”, it says “herding”. I just feel bad for the team that studies the manual, reads the rule and says “I know what herding is” I watch “one man and his dog(1)”, we cannot “herd” the buckyballs but we can “push” them. They go to the competition, are promptly DQed and leave feeling confused as to what they did wrong.

I think the rule was probably designed to stop powerhouse teams taking control of all the buckyballs to the detriment of new teams with a clawbot just trying to score a few points. I didn’t think it was designed to punish what may be unintentional mistakes during the autonomous period that were seen as intentional for whatever reason.

It reminds me of the refs at out first competition last year that managed to turn the rule that said “sacks may not be intentionally placed on the opponents robot” into “de-scoring is illegal if any sack falls onto the opponent”.

(1) obscure reference to BBC TV program featuring sheep dog trials

^ James is right, I oversimplified. -_-

My point can be more generalized though: There is a grey area, instead of trying to exactly define what must happen in it, let’s leave it up to a judgement and common sense. <-- Is an idea I promote not the reality of how refs are treating this.

If you take it literally (which seems to be going on a lot) you get into a highly noisy area where there are contradictions and inconsistencies, however if you back out and evaluate it with a gain of salt the rule isn’t that bad.

That’s like, all I meant to say in that post. I really don’t know what to do here. There are issues I guess, either way - this is the current state of SG8 which is what this thread is about.

I think the public debate is good. I don’t think it’s a bad rule, but it does use specific language and I think the extrapolation of the rule to include brief intentional contact with objects being considered as possession is wrong.

Taking a step back.
The carrying, herding and trapping language in the rule is just given as examples. It actually says

The “actively controlling” part should really be what we are debating.