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-   -   'Trivial' Posession allowed? (http://www.chiefdelphi.com/forums/showthread.php?t=127280)

jvriezen 27-02-2014 14:26

'Trivial' Possession allowed?
 
The glossary defines POSSESS like this:

POSSESS: (for a ROBOT) to
1) carry (move while supporting BALLS in or on the ROBOT),
2) herd (repeated pushing or bumping),
3) launch (impel BALLS to a desired location or direction via a MECHANISM in motion relative to the ROBOT),
or
4) trap (overt isolation or holding one or more BALLS against a FIELD element or ROBOT in an attempt to shield them) a BALL.

Item 4 is most likely intended to be applicable to POSSESSING an opponent's ball, but there is no reason it should not also be applicable to posessing your own ball, for purpose of recording ASSISTS. The ball is being "shielded" from the defensive robot bull-dozing it.

So, consider scenarios:

1) Two Red bots travel side by side with a Red ball 'sandwiched' between them (maybe in co-designed mechanisms or just between gapped bumpers) and travel from one zone to the next. If either bot were to have not been there, the ball would have fallen away. Two ASSISTS?

2) One bot is carrying the ball from one zone to another, and briefly opens its claw which would normally let the ball fall out, but a partner bot has an appendage (or side wall of bot) there preventing it from falling out. The claw re-closes to grab the ball. Two ASSISTS?

3) One bot is carrying the ball from one zone to another, and does not release its 'grip' on the ball, but a partner bot presses on the ball with an appendage (or bumper or any robot part) Two ASSISTS?

4) One bot has the ball in a cradle such that a sudden acceleration would cause the ball to be lost (no 'grip', just a ball carry that relies on gravity). A partner bot presses against the ball in the cradle. Again, the cradle bot has visited two zones. Two ASSISTS ?

Peter Matteson 27-02-2014 14:46

Re: 'Trivial' Posession allowed?
 
Quote:

Originally Posted by jvriezen (Post 1350563)
1) Two Red bots travel side by side with a Red ball 'sandwiched' between them (maybe in co-designed mechanisms or just between gapped bumpers) and travel from one zone to the next. If either bot were to have not been there, the ball would have fallen away. Two ASSISTS?

2) One bot is carrying the ball from one zone to another, and briefly opens its claw which would normally let the ball fall out, but a partner bot has an appendage (or side wall of bot) there preventing it from falling out. The claw re-closes to grab the ball. Two ASSISTS?

3) One bot is carrying the ball from one zone to another, and does not release its 'grip' on the ball, but a partner bot presses on the ball with an appendage (or bumper or any robot part) Two ASSISTS?

4) One bot has the ball in a cradle such that a sudden acceleration would cause the ball to be lost (no 'grip', just a ball carry that relies on gravity). A partner bot presses against the ball in the cradle. Again, the cradle bot has visited two zones. Two ASSISTS ?

1). I have no clue how that will be ruled if anyone pulls it off. I think the correct answer is no alliance will likely pull it off so the question is moot.

2-4) None of these would be possesion by both robots. To any casual obsever and by the other definitions the first robot never relinquishes control of the ball. You will not win an arguement like this with the referees because they will be calling obvious control for posession.

Gregor 27-02-2014 14:51

Re: 'Trivial' Posession allowed?
 
Quote:

Originally Posted by Peter Matteson (Post 1350574)
2-4) None of these would be possesion by both robots. To any casual obsever and by the other definitions the first robot never relinquishes control of the ball. You will not win an arguement like this with the referees because they will be calling obvious control for posession.

Could you cite a rule?

Peter Matteson 27-02-2014 15:07

Re: 'Trivial' Posession allowed?
 
Quote:

Originally Posted by Gregor (Post 1350581)
Could you cite a rule?

The definitions of carrying and herding.

It comes down to whether or not an observer can tell which robot is in control of the ball.

In all three of those cases someone whatching the game will rightly believe that the first robot is still carrying or hearding by definition, which they are.

The caveats that the OP uses to say control are relinquished are not obervable by a referee in the flow of the game and nebulious at best. Also the first robot is clearly still carrying or herding in all the descriptions.

Therefore some one watching and scoring the game would rule that possesion has never changed.

Again it's pointless to argue this because the chances of 2 teams building robots to facillitate anything but option 1 and fairly low, and as I said before actually pulling that off would be tough.

Racer26 27-02-2014 15:12

Re: 'Trivial' Posession allowed?
 
Quote:

Originally Posted by Peter Matteson (Post 1350592)
The definitions of carrying and herding.

It comes down to whether or not an observer can tell which robot is in control of the ball.

In all three of those cases someone whatching the game will rightly believe that the first robot is still carrying or hearding by definition, which they are.

The caveats that the OP uses to say control are relinquished are not obervable by a referee in the flow of the game and nebulious at best. Also the first robot is clearly still carrying or herding in all the descriptions.

Therefore some one watching and scoring the game would rule that possesion has never changed.

Again it's pointless to argue this because the chances of 2 teams building robots to facillitate anything but option 1 and fairly low, and as I said before actually pulling that off would be tough.

Yeah, sure, but there is no rule that states or implies that two ROBOTs on the same ALLIANCE cannot be simultaneously in POSSESSION of the same BALL.

Justin Montois 27-02-2014 15:13

Re: 'Trivial' Posession allowed?
 
Quote:

Originally Posted by Peter Matteson (Post 1350574)
1). I have no clue how that will be ruled if anyone pulls it off. I think the correct answer is no alliance will likely pull it off so the question is moot.

2-4) None of these would be possesion by both robots. To any casual obsever and by the other definitions the first robot never relinquishes control of the ball. You will not win an arguement like this with the referees because they will be calling obvious control for posession.


I think in every scenario the OP laid out Two assists should be counted. ASSISTS are defined by Unique POSESSION in a unique ZONE. Nowhere in the rules does it say that 2 robots can't POSSES a ball at the same time.

In fact, a Q & A addressed this concern.... (Question #415)

Q: If one robot is carrying a ball, can it create a trap with a second alliance robot while maintaining the carry?

A: Generally, yes, but the specific MATCH situation will determine the Referee's decision.

If FIRST Referees plan on calling matches based on "obvious" control and not calling matches based on the rules then you're going to have a lot of upset coaches, drivers and teams.

FIRST really dropped the ball in not having a section of the rules to differentiate possession of your alliance ball versus an opponent ball.

If this doesn't get addressed, I fully expect to get 3 assists when each one of my alliance robots...

- "Traps" the ball against the wall in each zone for even a split second.

-"Herds" the ball by simply driving into it twice in each zone.

-"Launches" the ball by driving into it once with my drive train (Which I consider a Mechanism) in each zone. (You could argue this one but you get the point)

ETC, ETC, ETC....

bduddy 27-02-2014 15:24

Re: 'Trivial' Posession allowed?
 
Quote:

Originally Posted by Justin Montois (Post 1350596)
-"Launches" the ball by driving into it once with my drive train (Which I consider a Mechanism) in each zone. (You could argue this one but you get the point)

One of the team updates specifically mentioned that it must be an active mechanism, in motion relative to the rest of the robot. So if you expect possession for that, you're going to be disappointed.

jvriezen 27-02-2014 15:28

Re: 'Trivial' Posession allowed?
 
Quote:

Originally Posted by bduddy (Post 1350606)
One of the team updates specifically mentioned that it must be an active mechanism, in motion relative to the rest of the robot. So if you expect possession for that, you're going to be disappointed.

Agreed. Bopping the ball with robot drive motion is specifically allowed as defensive tactic without incurring a POSSESS penalty.

Nuttyman54 27-02-2014 15:44

Re: 'Trivial' Posession allowed?
 
Quote:

Originally Posted by Justin Montois (Post 1350596)
I think in every scenario the OP laid out Two assists should be counted. ASSISTS are defined by Unique POSESSION in a unique ZONE. Nowhere in the rules does it say that 2 robots can't POSSES a ball at the same time.

Agreed. In addition to Q&A, I think that the rule wording implicitly states that two robots can possess the same ball simultaneously. I laid out that argument here.

For completeness, I'll summarize the argument:
Given that the manual states that holding a ball against a robot is possession (Possession definition part 4, "trapping"), both robots are holding the ball against the other robot (Newton's laws), therefore both robots must be awarded possession simultaneously. There is no other way to satisfy that part of the rules.

That being said, I agree that without the robot originally in possession of the ball demonstrating that they have relinquished control, it will be hard to get that call from the refs. In order to have a chance, I think it has to be clear that both robots are a necessary part of the "trap" to have dual possession awarded.

BBray_T1296 27-02-2014 16:05

Re: 'Trivial' Posession allowed?
 
I think the "grandmother clause" will come into effect here.

If the refs cannot instantly tell it was a possession, it will be very difficult to convince them post-match, and therefore is not nearly the best assist attempt, for that very reason.

If I saw 2 robots cradling the ball between them as it went down the field, I would say they were both in possession, provided it was obviously different than one robot possessing, and one robot playing some sort of counter defense.

In #2, this scenario would likely be difficult to tell what you were doing, as if somebody rolled up to another robot, opened and then shut the claw holding the ball, it would seem to me like operator error or a decidedly failed or aborted attempt to actually hand the ball over. If you, say dropped the ball onto the robot, displayed lack of self control of the ball (claw obviously not in possession to the nearby ref)

In #3, no, as the second robot never had any amount of control over the ball, the first robot had nothing but total control over the ball the entire time

#4. It actually depends. Say my team has nothing but a kit bot. If another team gently bumps the ball (or drops it) onto me and proceeds to guard the ball from falling off of me while I drive down the field passively (not with a claw 90% enclosed around the robot).

Now. These are simply my personal opinions, and have no hard rules backing them, but I would like say this:

Don't try to lawyer your way into a few extra points after a match. The ref's decision is correct unless proven incorrect. It is more than likely that you will have little to no way of actually proving your case, and if the ref says "no" to your argument then you don't get the points. period. Make your intent obvious during a match and you will be rewarded with a much less stressful weekend.

Harman341 27-02-2014 16:09

Re: 'Trivial' Posession allowed?
 
If two robots traveled the whole field with a ball lodged between them, it should count as one pass. I wouldn't make it your game plan though, at least not until week 2.

jvriezen 27-02-2014 16:10

Re: 'Trivial' Posession allowed?
 
Quote:

Originally Posted by Nuttyman54 (Post 1350619)
Agreed. In addition to Q&A, I think that the rule wording implicitly states that two robots can possess the same ball simultaneously. I laid out that argument here.

For completeness, I'll summarize the argument:
Given that the manual states that holding a ball against a robot is possession (Possession definition part 4, "trapping"), both robots are holding the ball against the other robot (Newton's laws), therefore both robots must be awarded possession simultaneously. There is no other way to satisfy that part of the rules.

That being said, I agree that without the robot originally in possession of the ball demonstrating that they have relinquished control, it will be hard to get that call from the refs. In order to have a chance, I think it has to be clear that both robots are a necessary part of the "trap" to have dual possession awarded.

I'd maybe not go quite that far (which is why I had the multiple scenarios). In cases where the ball is safely gripped or cradled (3,4) does the second bot also satisfy the 'overt' and 'shielding' aspect that is seemingly required for a trap to be a POSSESSION ?

jvriezen 27-02-2014 16:17

Re: 'Trivial' Posession allowed?
 
Quote:

Originally Posted by BBray_T1296 (Post 1350635)
Don't try to lawyer your way into a few extra points after a match. The ref's decision is correct unless proven incorrect. It is more than likely that you will have little to no way of actually proving your case, and if the ref says "no" to your argument then you don't get the points. period. Make your intent obvious during a match and you will be rewarded with a much less stressful weekend.

Just to clarify... My reason for the post was not that I wanted to try any of these things specifically. I can certainly see teams that routinely collaborate recognizing scenario 1 as a valid way to get two ASSISTs without the ball hitting the floor or being 'tossed' in a manner subject to losing control. The other scenarios were just included to see how far people think that envelope can be pushed.

In fact, if a ball is 'trapped' between three bots, all traveling down field together, I would say that is a clearly valid way to get three ASSISTS (assuming all three zones traversed) Think of three mecanum bots forming a triangle cavity between them. When they get to the scoring zone, one of them picks up the ball and shoots.

jvriezen 27-02-2014 16:21

Re: 'Trivial' Posession allowed?
 
Quote:

Originally Posted by Harman341 (Post 1350637)
If two robots traveled the whole field with a ball lodged between them, it should count as one pass. I wouldn't make it your game plan though, at least not until week 2.

Not clear what you are claiming here. 'pass' is not a defined term. Do you mean one ASSIST, or one 'pass' that implies two ASSISTs ?

Nuttyman54 27-02-2014 16:27

Re: 'Trivial' Posession allowed?
 
Quote:

Originally Posted by jvriezen (Post 1350639)
I'd maybe not go quite that far (which is why I had the multiple scenarios). In cases where the ball is safely gripped or cradled (3,4) does the second bot also satisfy the 'overt' and 'shielding' aspect that is seemingly required for a trap to be a POSSESSION ?

Sorry for the confusion, I didn't mean to imply that I think all of the presented scenarios qualify. I was simply trying to say that I agreed with Justin's interpretation that the rules allow for simultaneous possession by two robots.

It is still up to interpretation as to what actually qualifies as "trapping", but the rules regarding trapping seem to make it clear that multiple robots can possess the same ball at the same time in certain cases.


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