# T-boning is a pin, right?

In our last weekend competition, I perceived the refs did not understand that t-boning is a pin that should be counted out and penalized if sustained for too long. Several times, I saw a robot held in place by sideways midfield force by another robot, and refs not counting out the pin. Maybe the topic hasn’t come up in a while, and some refs are unaware that a pin against the wall / field element is not the only kind of pin? Anyone else seeing this?

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According to the rules, a t-bone is not a pin. Against some robots, and some drivers, a t-bone can effectively pin but that doesn’t change the definition of a pin from the rules.

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“A ROBOT is PINNING if it is preventing the movement of an opponent ROBOT by contact, either direct or transitive (such as against a FIELD element).”

That’s a direct quote from G202. Note also that per the blue box, desired direction of travel is NOT a consideration.

Translation: If your robot can move, even if it is not the way you want to go, it’s not a pin.

This does change from year to year, to be fair–some years T-bones are counted as pins, some years they are not. But this year, given the rule and the blue box, it’s fair to say that T-bones are not pins. You’re welcome to put a student in the question box to discuss this with the Head Ref at your event, or ask a Q&A for clarification–but as written, I would not say that T-bone pins are actually pins by rule.

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from the blue box on G202:

“A team’s desired direction of travel is not a consideration when determining if a
ROBOT is PINNED.”

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Even if tbone was considered a pin, it would not result in a penalty due to the bots moving more than 6ft.

"A ROBOT is considered PINNED until the ROBOTS have separated by at least 6 ft. (~183 cm) from each other, either ROBOT has moved 6 ft. from where the PIN initiated "

With the t-bones I saw, the robot could not move in any direction.

Could not? Or would not?

In my experience, in a T-bone, the robot can usually move, albeit in a circle.

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Could not move

All I can say is… several times I saw robots held from the side by force by other robots, and they seemingly could not move at all. They weren’t being pushed sideways; they were being held in place. This seems to qualify as a pin according to the rules.

And all I’m going to say is: not a pin, by rule.

Whether or not it should be is another discussion entirely. I can’t say I’ve seen the question pop up in any Q&As this year. I can’t say that I’ve heard of it being called that way at any events this year.

By all means, ask the question in the official Q&A. It may be interesting to see the response…

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“either direct or transitive”… the t-bone prevention of any movement seems to be the “direct” case

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I have never seen a t-bone where the robot being t-boned is not able to move forward/backward; if you have please post a link! A t-bone does not prevent movement, but it makes it so the affected robot can’t go in the direction they want to go. Very effective defense, but not a pin.

One solution to the t-bone issue is to replace all of your wheels with omni wheels. It’s a whole lot of fun, and highly recommended if you haven’t tried it before! This solution introduces other drive issues on an FRC field that you might not like.

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Ah, the lost art of Aluminum Magnetry.

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You’ve never seen a robot T-boned into a wall and can’t move?

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The wording “…such as…” would seem to imply that a field element is not required to complete a pin. I read this as “A ROBOT is PINNING if it is preventing the movement of an opponent ROBOT by contact…” The rest of the sentence is giving examples.

How does it not meet this definition if two robots are in contact, preventing one from moving?

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That is a pin. This is a t-bone:

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OP is specifically talking about “pins” NOT up against a wall.

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got it, missed that part. I agree then, just T-boning by itself in the middle of the field isn’t a pin.

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I don’t have a video for ya. I don’t have the time to dig one up, but it is possible to T-bone a tank drive robot and it not be able to drive out of it. Lots of past discussion on CD on the choice of bumper fabric to defend from this sort of defense. Search is your friend.

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When a robot is t-boned they can still provide motion forward and backward, even if they can’t escape the t-bone. Thus not a pin. I’m not sure if maybe there is something lost in translation here.

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And when in an open field, you can move “away” from the robot T-boning you. Not all robots can do this because of their design (tank drive) but its physically possible to move away therefore their movement is not being prevented. In a T-bone, their movement is just being restricted to a certain direction (which the blue box says is okay as we don’t consider desired direction of travel)