G13, G44 and Pinching Rollers

[jspatz1]

I see the use of pinching rollers this year as a high-risk, high-reward gamble for those that chose to employ them, and was sort of the elephant in the room all season. Some had the flexibility or verticle freedom to leave the ball in contact with the ground when the robot experienced small bumps or elevations. Some did not. If you chose to grip the ball, you were making a judgement that the benefits of doing so outweighed the risks of incurring penalties when your robot experienced motions that caused the ball to come out of contact with the carpet momentarily. For those that had no flexibility in their gripper, it was almost a given that at some moment in the match they would experience some motion that would cause them to technically carry the ball when bumped by another robot, when going over a small lip or bump (such as the lip in front of the bumps), when tilting slightly through their own movements, or when pushing a ball into a goal. The real question was whether the referees would catch these momentary lifts, or whether they would interpret them to be penalized lifts. In my opinion, incurring a penalty because another robot bumped you when you were gripping a ball is not the kind of situation that is being refered to in the "one robot cannot cause a penatly for another robot" rule. Significant contact between robots is expected and part of the game. If it was the nature of your gripper that such robot contact caused you to lift the ball, then that was a vulnerablility of your design and a risk you chose to take. In our case, we interpreted the carry rule as absolute, and chose to capture the ball against the carpet so that is was impossible to inadvertantly carry. But we recognize that a pinching roller was an effective and worthwhile tactic for those that did it well.