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DMike 07-02-2014 08:10

What is considered a catch
 
Are there any "possession, control" rules ? What if the ball passes over the truss and falls into a waiting "catching bot", but then bounces out. Is this considered a catch?

TheKeeg 07-02-2014 08:23

Re: What is considered a catch
 
Quote:

Originally Posted by DMike (Post 1339021)
Are there any "possession, control" rules ? What if the ball passes over the truss and falls into a waiting "catching bot", but then bounces out. Is this considered a catch?

3.1.4:
A CATCH occurs when a BALL SCORED over the TRUSS by a ROBOT’S ALLIANCE partner is POSSESSED by that ROBOT before contacting the carpet, the ROBOT which SCORED the TRUSS, or HUMAN PLAYER.

The ref needs to see obvious possession before the ball hits the ground, i.e the ball cant just hit your catcher and bounce right out without you "holding" it first.
At least that is what i got from it.

JamesCH95 07-02-2014 08:36

Re: What is considered a catch
 
I would most certainly apply the 'grandmother' rule to this. That is to say if your grandmother (or someone unfamiliar with FRC and its detailed rules) wouldn't think a robot caught the ball, then you didn't really catch it.

If the ball lands in/on your robot and bounces out, that's probably not a catch.

DjScribbles 07-02-2014 08:51

Re: What is considered a catch
 
POSSESSION is defined by the manual under G12 as follows:


Quote:

An ALLIANCE may not POSSESS their opponent’s BALLS. The following criteria define POSSESSION :

“carrying” (moving while supporting BALLS in or on the ROBOT),
“herding” (repeated pushing or bumping),
“launching” (impelling BALLS to a desired location or direction via a MECHANISM in motion relative to the ROBOT), or
“trapping” (overt isolation or holding one or more BALLS against a FIELD element or ROBOT in an attempt to shield them).
Blue Box:
Quote:

Examples of BALL interaction that are not POSSESSION are

A. “bulldozing” (inadvertently coming in contact with BALLS that happen to be in the path of the ROBOT as it moves about the FIELD) and

B. “deflecting” (a single hit to or being hit by a BALL that bounces or rolls off the ROBOT).

A BALL that becomes unintentionally lodged on a ROBOT will be considered POSSESSED by the ROBOT. It is important to design your ROBOT so that it is impossible to inadvertently or intentionally POSSESS an opponent’s BALL.
Additionally Q&A has made some statements with regards to blocking that should also apply to catching:

Q177:
Quote:

Generally, if [a] MECHANISM is in motion relative to the ROBOT at the time of impact, it is "launching" and thus POSSESSION. If the MECHANISM is not in motion relative to the ROBOT, it is considered "deflecting" and not POSSESSION.

pntbll1313 07-02-2014 09:34

Re: What is considered a catch
 
Quote:

Originally Posted by JamesCH95 (Post 1339029)
I would most certainly apply the 'grandmother' rule to this. That is to say if your grandmother (or someone unfamiliar with FRC and its detailed rules) wouldn't think a robot caught the ball, then you didn't really catch it.

If the ball lands in/on your robot and bounces out, that's probably not a catch.

Do not apply the 'grandmother' rule to this. There is a clear definition in the manual.

A CATCH occurs when a BALL SCORED over the TRUSS by a ROBOT’S ALLIANCE partner is POSSESSED by that ROBOT before contacting the carpet, the ROBOT which SCORED the TRUSS, or HUMAN PLAYER.

You just need to POSSESS the ball. DjScribbles has quoted the places in the manual and QA relevant to the definition of POSSESSION.

CATCH != catch as your grandmother may think.

M.O'Reilly 07-02-2014 09:41

Re: What is considered a catch
 
2 feet down and a football move common to the game? :p

sorry, couldn't help it.

JamesCH95 07-02-2014 09:52

Re: What is considered a catch
 
Quote:

Originally Posted by pntbll1313 (Post 1339060)
Do not apply the 'grandmother' rule to this. There is a clear definition in the manual.

A CATCH occurs when a BALL SCORED over the TRUSS by a ROBOT’S ALLIANCE partner is POSSESSED by that ROBOT before contacting the carpet, the ROBOT which SCORED the TRUSS, or HUMAN PLAYER.

You just need to POSSESS the ball. DjScribbles has quoted the places in the manual and QA relevant to the definition of POSSESSION.

CATCH != catch as your grandmother may think.

If you're willing to risk a non-reversible ref's call on it, go ahead.

I see a few ways to interpret what's in the manual:

"carrying" - passes the grandmother check

"herding" - if you can repeatedly bump/push the ball before it hits the ground, you deserve a medal

"launching" - Very high-risk IMO, relies on ref's non-reversible call/judgement being the same as yours with regards to a mechanism being in motion relative to the robot; you must also hit the ball mid-air with a moving mechanism which doesn't strike me as practical and would likely result in hunting down the ball, costing you and your alliance precious time. While possibly within the letter of the rule, it is not within the spirit or intent of the rule IMO.

"trapping" - if you can pin a ball between your robot and a field element mid-air, you deserve a medal, and i think that would also pass the grandmother rule too

So, I suppose you're right in a sense: there are a few cases where a by-the-letter interpretation of the rules results in a CATCH the grandmother rule does not. Though IMO one better think long and hard about the practicality and reliability of making a 'non-grandma-approved' CATCH. I suggest following the grandmother rule from a practicality and reliability standpoint.

pntbll1313 07-02-2014 10:11

Re: What is considered a catch
 
Quote:

Originally Posted by JamesCH95 (Post 1339073)
If you're willing to risk a non-reversible ref's call on it, go ahead.

I didn't say anything about it being worth it to risk this. There are many threads out there from the beginning of the season arguing the ambiguity of a CATCH. I'm sure there will be quite a few refs that call a launch a CATCH, and quite a few that don't. That's one of the tough things about this particular rule. If you are a high caliber team you will of course try to design a mechanism capable of performing a CATCH and actually catching the ball for control reasons.

If you are a low resource team and were only able to field a moving lunch tray there are other ways to get a CATCH. If you have a spinning paddle on top of your robot designed to hit the ball in the forward direction all you need to do is park under where the ball will land. If the ball hits your paddle and goes forward it would, according to the manual and QA, be considered a CATCH. Grandma wouldn't think so because it is not a catch, but it is still a CATCH.

JamesCH95 07-02-2014 10:13

Re: What is considered a catch
 
Quote:

Originally Posted by pntbll1313 (Post 1339092)
I didn't say anything about it being worth it to risk this. There are many threads out there from the beginning of the season arguing the ambiguity of a CATCH. I'm sure there will be quite a few refs that call a launch a CATCH, and quite a few that don't. That's one of the tough things about this particular rule. If you are a high caliber team you will of course try to design a mechanism capable of performing a CATCH and actually catching the ball for control reasons.

If you are a low resource team and were only able to field a moving lunch tray there are other ways to get a CATCH. If you have a spinning paddle on top of your robot designed to hit the ball in the forward direction all you need to do is park under where the ball will land. If the ball hits your paddle and goes forward it would, according to the manual and QA, be considered a CATCH. Grandma wouldn't think so because it is not a catch, but it is still a CATCH.

I'm not disagreeing with you, I think all of your points are valid, I am just explaining why I would choose to follow the grandma rule. :]

Sorry if my original post did not convey that intent :o

Josh Fritsch 07-02-2014 10:15

Re: What is considered a catch
 
Quote:

Originally Posted by pntbll1313 (Post 1339092)
I didn't say anything about it being worth it to risk this. There are many threads out there from the beginning of the season arguing the ambiguity of a CATCH. I'm sure there will be quite a few refs that call a launch a CATCH, and quite a few that don't. That's one of the tough things about this particular rule. If you are a high caliber team you will of course try to design a mechanism capable of performing a CATCH and actually catching the ball for control reasons.

If you are a low resource team and were only able to field a moving lunch tray there are other ways to get a CATCH. If you have a spinning paddle on top of your robot designed to hit the ball in the forward direction all you need to do is park under where the ball will land. If the ball hits your paddle and goes forward it would, according to the manual and QA, be considered a CATCH. Grandma wouldn't think so because it is not a catch, but it is still a CATCH.

Couldn't agree more. Both POSSESSION and CATCH are clearly defined within the rules and Q&A quoted above.

There is no reason to bring opinions on practicality and risk into the discussion as each team must weigh that on their own when designing mechanisms within the rules defined. The OP asked a specific question and the response given was correct.

ToddF 07-02-2014 10:23

Re: What is considered a catch
 
Something to keep in mind is that the same "possession" definition that applies to catching a ball coming over the truss also applies to possessing an opponents ball, which is a technical foul.

If you are prepared to argue that deflecting your own ball should count as a catch, you should also be prepared, as a matter of gracious professionalism, to argue that by deflecting your opponents ball you deserve a technical foul.

Duncan Macdonald 07-02-2014 11:57

Re: What is considered a catch
 
I anticipate the "desired location or direction" being called very strictly with regards to catching to prevent a team from spinning a baseball bat over their robot to earn catch points. If a robot has an active mechanism directing the ball towards the next zone/far wall/friendly robot reliably I expect catch points to be awarded. I am comfortable with my interpretation of the rule but it is slightly at odds with the traditional (grandmother's) definition.

My grandmother's opinion of the rules doesn't bother me this year since an "assist" could be:
-Robot Red 1 pins ball against wall for a couple of seconds
-Every robot ignores the ball for 90 seconds
-Robot Red 2 collects it, drives it the length of the field, and scores it

-Red robot 1 recieves the ball and throws it the length of the field
-Blue robot bumps it back to the original zone ("traditionally considered incomplete or a turnover)
-Red robot 2 collects and scores

AFron10 07-02-2014 13:12

Re: What is considered a catch
 
Sorry that this may be a little off topic but when a human player catches the ball over the truss, then places the ball in a robot without the ball ever touching the ground, does that alliance receive catch points in that cycle? I apologize if this is already stated in the Q&A or the manual.

BBray_T1296 07-02-2014 13:23

Re: What is considered a catch
 
Quote:

Originally Posted by AFron10 (Post 1339166)
Sorry that this may be a little off topic but when a human player catches the ball over the truss, then places the ball in a robot without the ball ever touching the ground, does that alliance receive catch points in that cycle? I apologize if this is already stated in the Q&A or the manual.

No, a catch by a human player is ineligible for catch points, however, when he (or she, I might add :P) gives the ball to a [different] awaiting robot, assist points are received, along with the toss points.

Im not in a place to go scrounging through rules but I recall discussing this elsewhere on CD

DMike 07-02-2014 13:33

Re: What is considered a catch
 
With the obvious overwhelming effort put into the rules and more rules. I would think that the definiton of "Catch" would be absolute. Ie. in possession for (X) amount of time, or mandatory movement of the bot after catching. Now we want to enact the vague "grandmothers rule", I would argue that inadvertently ending up with your opponents ball in your bot doesn't define possession, due to complete lack of intent. In fact are there any rules preventing an alliance from intentionally placing the ball in an opponents bot?


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