View Full Version : Can you catch your own ball?
mistersands
06-01-2014, 11:15
So the rules say :
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 or HUMAN PLAYER
I'm a little confused. Does "that ROBOT" refer to the alliance partner who scored the ball over the truss, or the robot who has the alliance partner?
In other words, can you launch your ball over the truss and catch it on the other side? Or does it have to be separate robots?
So the rules say :
I'm a little confused. Does "that ROBOT" refer to the alliance partner who scored the ball over the truss, or the robot who has the alliance partner?
In other words, can you launch your ball over the truss and catch it on the other side? Or does it have to be separate robots?
Yes, you can catch it. No, no catch points will be awarded.
protoserge
06-01-2014, 11:20
FRC Q&A is the official source for answers to your questions. Anything on CD will not be an official response (it may be correct, however). Please post this on the FRC Q&A (https://frc-qa.usfirst.org)
Alan Anderson
07-01-2014, 10:26
The only way I can parse the rule cleanly is for "that ROBOT" to be the ROBOT whose ALLIANCE partner SCORED the BALL over the TRUSS. It is clear to me that you won't earn points for catching a ball you threw yourself.
BBray_T1296
07-01-2014, 15:43
But I (as "that ROBOT") am an ALLIANCE robot myself. My robot is just as much an ALLIANCE partner as the other two
JohnSchneider
07-01-2014, 16:02
But I (as "that ROBOT") am an ALLIANCE robot myself. My robot is just as much an ALLIANCE partner as the other two
The rules clearly say that you cannot receive catch points off a ball that you also threw.
It'd be kinda cool to do and particularly advantageous if both alliance partners aren't moving well. It's an edge case though.
Alan Anderson
07-01-2014, 16:27
My robot is just as much an ALLIANCE partner as the other two
I am unable to make the leap to say that you are your own partner.
I am unable to make the leap to say that you are your own partner.
To understand alliances you must understand alliances. (a la the recursion quote).
But, seriously, I view the "partner" as referring to two different robots. The sentence is poorly worded and needs clarification, as the "that ROBOT" portion seems to indicate the same robot.
Bob Steele
07-01-2014, 17:03
So the rules say :
I'm a little confused. Does "that ROBOT" refer to the alliance partner who scored the ball over the truss, or the robot who has the alliance partner?
In other words, can you launch your ball over the truss and catch it on the other side? Or does it have to be separate robots?
the rule states a robot's alliance partner throws and that robot catches.
That is probably being used as an adjective to delineate a reference to "a robot" It is grammatically awkward.
Better wording would be
A CATCH occurs when a BALL SCORED over the TRUSS by a ROBOT is POSSESSED by either of the two non-truss scoring ROBOTS from the same ALLIANCE as the truss scoring robot before contacting the carpet or HUMAN PLAYER
This kind of relates to the originally proposed question...
Do you HAVE to catch the ball thrown over the truss in order to get the truss points, or does the ball just have to be thrown over the truss to get those points?
I would ask on FRC Q&A, but it's not open yet, so I was hoping that someone on CD would be able to clarify for me.
Thanks.
This kind of relates to the originally proposed question...
Do you HAVE to catch the ball thrown over the truss in order to get the truss points, or does the ball just have to be thrown over the truss to get those points?
I would ask on FRC Q&A, but it's not open yet, so I was hoping that someone on CD would be able to clarify for me.
Thanks.
You have to get the truss in order to get the catch. However, I see nothing indicating that a catch is necessary to get truss points.
GaryVoshol
07-01-2014, 20:21
You have to get the truss in order to get the catch. However, I see nothing indicating that a catch is necessary to get truss points.
Correct. Else there would be no point in awarding 10 points separately. If you had to do both things to make either count, then they would just have defined a 20-point task.
Calvin Hartley
07-01-2014, 20:29
This kind of relates to the originally proposed question...
Do you HAVE to catch the ball thrown over the truss in order to get the truss points, or does the ball just have to be thrown over the truss to get those points?
A BALL is considered SCORED over the TRUSS if a ROBOT causes a BALL to pass though the infinitely tall plane that is bounded by the top of the TRUSS and the TRUSS POLES toward the ALLIANCE’S GOALS (e.g. a red BALL towards the red GOALS). This plane is depicted in yellow in Figure 3-3.
The rule never mentions CATCHING the BALL in regards to TRUSS scoring. Read the manual for what it says, no need to assume anything else. It does not say you need to catch the ball to score. Hope this helps.
The rule never mentions CATCHING the BALL in regards to TRUSS scoring. Read the manual for what it says, no need to assume anything else. It does not say you need to catch the ball to score. Hope this helps.
Thanks guys. I thought that they didn't have to be coorelated, but I wasn't too sure.
Kevin Leonard
09-01-2014, 20:59
Now what I am wondering is:
If you catch your own ball, then pass it to your alliance partner without it touching the ground, is that a legal catch? Because the ball hasn't touched the ground before it is possessed by the partner robot.
The rules make me think "Yes, it would" because of the possession rules, but my gut says "No", because that's not exactly the intent of catching, is it?
Alan Anderson
09-01-2014, 21:26
Now what I am wondering is:
If you catch your own ball, then pass it to your alliance partner without it touching the ground, is that a legal catch? Because the ball hasn't touched the ground before it is possessed by the partner robot.
That's clever. The rules as written seem to say that this scenario indeed earns the catch points.
That's clever. The rules as written seem to say that this scenario indeed earns the catch points.
Not quite. The blue box specifies that catch points must be immediately preceded by truss points. Thus, no truss points on the throw, no catch points on catching it. Realizing that blue boxes aren't rules per se, they do provide a really good window into what the GDC intended.
Kevin Leonard
09-01-2014, 21:30
That's clever. The rules as written seem to say that this scenario indeed earns the catch points.
But I just found this in the Q&A:
"Q. Will CATCH points be awarded if the same ROBOT that scored over the TRUSS is the first to POSSESS the BALL? In other words, can a ROBOT CATCH its own toss over the TRUSS and earn points?
A. No."
Once again, though, the answer is still ambiguous. Although it seems to imply that that scenario is invalid.
But I just found this in the Q&A:
"Q. Will CATCH points be awarded if the same ROBOT that scored over the TRUSS is the first to POSSESS the BALL? In other words, can a ROBOT CATCH its own toss over the TRUSS and earn points?
A. No."
Once again, though, the answer is still ambiguous. Although it seems to imply that that scenario is invalid.
That did not seem ambiguous to me. Toss the ball over the truss, catch it yourself, no points.
If we can do it, we will do it a couple of times on Thursday as an exhibition of our capabilities to play in the higher scoring efforts.
TJ
Chris is me
10-01-2014, 00:21
Not quite. The blue box specifies that catch points must be immediately preceded by truss points. Thus, no truss points on the throw, no catch points on catching it. Realizing that blue boxes aren't rules per se, they do provide a really good window into what the GDC intended.
Why would there be no truss points on the throw?
Why would there be no truss points on the throw?
For the specific instance given (a robot that has caught their own thrown ball passing to another robot without the ball ever touching the ground), there are not one, but two throws. The first throw is over the truss; that throw gets truss points, but due to the GDC ruling, no catch points. The second throw is not over the truss, or if it is, it is not eligible for truss points due to those already being earned on the first throw, per 3.1.4. Under the referenced blue box, and the preceding text, catch points only follow when truss points are earned, not on subsequent throws.
So, the scenario and scoring as envisioned:
1) Redabot 1 throws a ball over the truss. 10 points (Truss), 10 total. (No further Truss points can be given for the cycle.)
2) Redabot 1 catches their throw. 0 points (GDC ruling, not a Catch), 10 total. Ball does not touch ground.
3) Redabot 1 throws to Redabot 2, who catches it. 10 points (Catch), 20 total. Eligible for Assist points, if positioning is correct.
However, as I'm reading the rules for this type of scenario...
1) Redabot 1 throws a ball over the truss. 10 points (Truss), 10 total. (No further Truss points can be given for the cycle.)
2) Redabot 1 catches their throw. 0 points (GDC ruling, not a Catch), 10 total. Ball does not touch ground.
3) Redabot 1 throws to Redabot 2, who catches it. 0 points (Catch not immediately preceded by Truss), 10 total. Eligible for Assist points, if positioning is correct.
I should have put the earlier post as, "No truss points given on the throw means that no catch points can be given on the catch; if truss points were given on the throw, then catch points could be given if the catch was made."
David Brinza
10-01-2014, 02:01
But I just found this in the Q&A:
"Q. Will CATCH points be awarded if the same ROBOT that scored over the TRUSS is the first to POSSESS the BALL? In other words, can a ROBOT CATCH its own toss over the TRUSS and earn points?
A. No."
Once again, though, the answer is still ambiguous. Although it seems to imply that that scenario is invalid.
What part of "No" do you not understand?
GaryVoshol
10-01-2014, 05:34
And thank goodness for this ruling.
Suppose this scenario: Bluebot1 throws the ball over the truss and catches it. Then Bluebot1 encounters heavy defense and there's a pushing match going on in the white zone for 20 seconds. Finally Bluebot1 gets free by going backwards almost to the alliance wall. It zooms down the field, and tosses the ball to Bluebot2. Really? You want that to qualify as a catch, for the throw over the truss that happened 30-40 seconds ago? And you want the refs to remember it so that they will score it?
Alan Anderson
10-01-2014, 07:51
What part of "No" do you not understand?
The part where two different questions are asked but only one answer is given. The Q&A response does not address the possibility of a second robot taking possession of the ball after the first one throws to itself.
The "in other words" restatement restricts the situation so that it does not match the scenario (where a robot catches its own thrown ball and hands it off to another robot without the ball touching the carpet). The letter of the rule doesn't prohibit contact with another robot before a valid catch, nor does it prohibit possession by another robot. I think the Q&A still has room in it for catch points to be awarded if something else occurs after what it answers happens.
I know there will continue to be discussions on this, but from what I take from the rules and the info in this thread, the catch points can only be earned directly after the ball travels OVER the truss earning the truss points. And so if a robot catches it's own ball after throwing it over the truss, no catch points will be earned, even if that robot throws it to another alliance robot directly after. And because the alliance has just then earned it's truss points for that cycle, backing up and thowing over the truss to an alliance robot won't help.
We can argue about the level of precision in the rule language but I'll eat a Talon* if points are awarded for robots throwing to each other.
* subject to checking they are 100% vegetarian
So it seems that catching your own ball even after traversing the truss will not result in catch points. It may be that the catch points are not as valuable as retaining control of the the ball. The time lost arranging for a catcher on your alliance and/or the time it takes to retrieve a dropped catch attempt may not be worth worrying about the lost points if you can reliably catch your own toss.
swwrobotics
13-01-2014, 17:37
Does anyone know how long a robot would have to "possess" a ball before it is considered caught? In other words, does a CATCH not count until the ball is scored in a goal without touching the carpet?
Does anyone know how long a robot would have to "possess" a ball before it is considered caught? In other words, does a CATCH not count until the ball is scored in a goal without touching the carpet?
Catch points count as soon as the Catch is made successfully. I seem to remember a Q&A on that topic.
swwrobotics
13-01-2014, 20:35
Catch points count as soon as the Catch is made successfully. I seem to remember a Q&A on that topic.
Oh, ok great thanks!
We can argue about the level of precision in the rule language but I'll eat a Talon* if points are awarded for robots throwing to each other.
From today's Team Update (http://frc-manual.usfirst.org/Updates/0#term 151) (CD discussion thread (http://www.chiefdelphi.com/forums/showthread.php?threadid=124643))
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.
So no Talon sandwich for me.
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