Ball Stuck Under Bridge When Balancing?

[kylelanman]

Our team, team 2481, had the following situation happen during Wisconsin Regional qual match 24 today:

Our team and team 1714 were balanced on the coopertition bridge when the match ended. Because there was a ball stuck under the bridge the bridge was not considered balanced. However, no foul was given for this situation. We were both awarded 1 QP because we were both fully supported by the bridge

The only rule referencing this situation that I could find is rule G:14 which states
"Strategies that use Basketballs to either aid or inhibit Balancing of any Bridge are not allowed.
Violation: Technical-Foul, and counting or discounting the affected Bridge as Balanced, as appropriate."

Does anyone know of any rules that would support this outcome?

[MagiChau]

The key word is "strategies." If the ball is accidentally placed (bounces off the robot e.g.) then it would not violate the rule. I do not know if the referee saw something that would make it seem like a strategy / intentional.

EDIT: The FMS could have detected the bridge as not balance so it did not award thr point as well.

[CalTran]

Also, and totally just guessing here, if the ball is under the coopertition bridge, which alliance would you penalize for it? Unless they saw who rolled the ball under with malicious intent, then there's not much penalty they can give.

Violation:Technical-Foul, and counting or discounting the affected Bridge as Balanced, as appropriate.

Technical Foul - already covered. Counting/Discounting the bridge? Well, it wouldn't be very penalizing if they automatically counted the bridge, and if they penalize one alliance for the bridge then the other one would inherently get penalized, because it's the coopertition bridge. I've never seen how the ref panel works, but I'm not sure there's a method for awarding one team the coop points without the other recieving as well.

[Retired Starman]

No one has to receive a foul when a ball gets under a bridge. Balls got stuck all the time during week one of competition. Even so, the presence of the ball there means the bridge is not balanced on its own, thus the scoring of one point each.

These things happen. Thankfully, FIRST redesigned the ball ramps after week one and there have been many fewer stuck balls since then.

Dr. Bob

Chairman's Award is not about building the robot. Every team builds a robot.

[kylelanman]

Originally Posted by Retired Starman

Even so, the presence of the ball there means the bridge is not balanced on its own.

Where does it indicate this in the manual?

[EricH]

Originally Posted by kylelanman

Where does it indicate this in the manual?

Section 2.2.5: A Bridge will count as Balanced if it is within 5° of horizontal.
[G40] When the final score is assessed per [G37], a Balanced Alliance Bridge will earn points based on the number of Alliance Robots completely supported by the Bridge, per Section 2.2.5,[...]

In other words, to be balanced, a bridge must be within 5 degrees of horizontal and completely support any robots that are on it.

Should a basketball be under a bridge, in contact with both the bridge and the floor/ball deflector, SOME of the weight of the robots on the bridge will be transferred through that basketball. It's physics. So, the surface of the bridge is taking all the weight... but a little weight is going through the floor instead of the pivot, assisting with balancing.

[kylelanman]

The robots are completely supported by the bridge. The bridge is not completely supported by the pivot. It states the robots have to be supported by the bridge and the bridge be balanced with in 5 degrees. It never states, that I can find, what is allowed to support the bridge.

[EricH]

If we're trying to balance a seesaw, and I've got my legs down contacting the ground while the seesaw is level, is the seesaw balanced?

If instead of legs I use a mound of dirt, is the seesaw balanced?

What about if I grab a playground ball or three and stick them under?





The seesaw might be leveled, but leveled and balanced are not the same thing. Synonyms? Yes. The same? No. I am typing this while sitting at a level desk, but it has no fewer than 2 points of support. You couldn't make the argument that it was balanced if you tried! (Balance generally tends to imply 1 point of support--see the definitions in Webster's.) Yet, your argument is that a bridge, with 2 points of support (one pivot point and one basketball), should be considered balanced. Remember, wherever the GDC refuses to define a term, they tell you to go to the common definition. They have defined balanced, yes--but they have not defined the support conditions necessary to be balanced. For those, we must go to the common definition. Guess what...

(I'm reasonably sure Tristan will be along shortly to dispute with one of us, or the GDC, or both.)



The other rule I'm going to point you to is [T13] and [T14]. You should have asked the Head Ref as soon as this happened/you discovered it. If you'd raised doubt in the Head Ref's mind, he might have called HQ/the GDC for clarification, and all that. Or he might know the rules better than CD does. Seeing as that apparently didn't happen, you're going to have to deal with one less CP for everyone in the match. And someone might need to post a question on Q&A.

[remulasce]

EricH, there is nothing in the rules that requires the Bridge to be supported by its center. As long as it is within whateverthenumberis degrees of horizontal and all robots touching it are fully supported by it, it counts for points.

Your "common definition" argument is invalid, because the word "Balanced" is explicitly defined:

Arena 2.25:

A Bridge will count as Balanced if it is within 5° of horizontal and all Robots touching it are fully supported by it

No other test is necessary. By your "pass-through" logic, it would also be near-impossible to receive 1 CP for a having two opposing robots fully supported by the Coopertition Bridge. Make a force diagram for all Robots touching the bridge. I doubt you would say the normal force is provided by the pivot point of the bridge- you would always identify it as Normal Force from the point of contact.

[EricH]

So, let me get this straight. Assuming that I don't make it look like I'm violating [G14], I can stuff as many basketballs as I like under a bridge and use them to balance, and the only thing I have to worry about is if the bridge is 5 degrees from horizontal or less.

I'm perfectly serious here. I can do that, assuming that I don't get called on [G14]. At least, that's what I'm hearing from everybody else. There's just something there that doesn't sound right, but I can't put my finger on it.

You know, this is starting to sound like the "trollbot" debate a few weeks back. There may be nothing in the rules against it, but it doesn't make any sense.

I would expect that one of three things will happen:
1) The GDC gets asked the question in Q&A, and hopefully answers. (Surprisingly, nobody thought to ask before now).
2) The head refs talk about it in their weekly meeting if someone goes and talks to their head ref, and most likely decides to go with precedent now that it's been set.
3) Nobody talks about it or asks about it and it crops up again in Week 5, Week 6, Championship Weekend, or the Championship. Wouldn't you love to be the head ref on Einstein potentially having to make this call? Admittedly, there you can call on the entire GDC for their opinion...

[remulasce]

EricH,
Yes, according to the rules, this would be correct. However, you are severely downplaying the importance of G14, which not only bans disrupting a balance attempt, but also using balls to aid in one. This is a technical foul violation, plus a bridge you aided in balancing would not count. Especially with the new ball ramps, I think it would be extremely difficult to "accidentally" manage to support the bridge usefully. You'd have to get it stuck perfectly within the bridge, go over to the other side to lower it, hope the ball doesn't fall out when you get on it from the other side, and then finally use that ball to help balance, all without the Refs noticing. I don't think the refs are that stupid.

You're throwing around "assuming you don't get called on [G14]" like that means it's probable. The whole point of that rule is to prevent the exact "doesn't feel right" feeling you're having. You may as well say the ability for robots to intentionally flip other robots without penalty doesn't feel right, assuming you don't get called on [G26]. Of course it doesn't! That's why there's a rule against it!

[kylelanman]

Arena 2.2.5
"A Bridge will count as Balanced if it is within 5° of horizontal and all Robots touching it are fully supported by it."

[G41]
If a Robot from each Alliance is Balanced on the Coopertition Bridge when the final score for a Qualification Match is assessed per Rule [G37], each Alliance earns 2 Coopertition Points. If the Coopertition Bridge is not Balanced, but a Robot from each Alliance is fully supported by the Coopertition Bridge, each Alliance will earn 1 Coopertition Point.

Both robots were fully supported by the bridge and the bridge was balanced. So if it was intentional then both teams should have gotten a technical foul and the bridge not count as balanced.

On top of everything a ball under the bridge makes it a lot hard to push down to drive on to and it should be obvious from all the struggling and the attempt to get the ball out that it was not intentional.