String Theory: <G22> at the Championships

[65_Xero_Huskie]

Originally Posted by jgannon

The referees are pretty good at spotting the corner of your bumper fabric going back over the line, so a string should be no trouble whatsoever.

Yea. It SHOULD be no problem.
But there have been times, not gonna specify, when refs have missed giant balls going over 6ft in the air over an overpass 2 times in 5 seconds. So i think the string would be very hard for some to see and people could get penalties for trying this type of thing.

[XXShadowXX]

Originally Posted by 65_Xero_Huskie

Yea. It SHOULD be no problem.
But there have been times, not gonna specify, when refs have missed giant balls going over 6ft in the air over an overpass 2 times in 5 seconds. So i think the string would be very hard for some to see and people could get penalties for trying this type of thing.

there is no need to insault the refree, there job is very hard and stressful...

[EricH]

Originally Posted by XXShadowXX

there is no need to insault the refree, there job is very hard and stressful...

He's stating something that happened. That's not insulting the refs, it's saying they didn't see it. There's a big difference there. I've seen refs not see things myself in soccer. It happens.

Now if he'd been grousing about it, that would be an insult.

[Bongle]

Originally Posted by Valley Raider

<G22> has caused 1000's of points in penalties. And I have not seen a single team intentionally drive backwards. I think if this rule had been examined more before the game was created this could have been avoided. That was the point I was trying to make.

You should think about <G22> a bit more, I think it shows that FIRST put lots of effort into deciding the penalties and their valuations.

Edit: What follows is incorrect. In cases where you're knocking off an opponent's trackball or freeing an alliance partner, the gain is or can be greater than 10 points.

Original:
Nobody will EVER break <G22> intentionally. Ever. Period. There is zero incentive to do so. There is nothing you can accomplish by breaking <G22> intentionally that will actually result in you scoring 10 points (or preventing your opponent from scoring 10 points). Complaining that <G22> only catches people who broke it unintentionally is stating the obvious. Nobody would break <G22> intentionally, doing so would guarantee a net loss in points.

I would argue that this property of <G22> means that FIRST did think very hard about the rules beforehand, and set the penalty score just high enough that nobody would ever bother breaking it on purpose, thus accomplishing their goal of a circular game.

[Alan Anderson]

Originally Posted by XXShadowXX

You people really need to give it up, after Sunday there will be a whole new game.

The new game doesn't arrive for eight and a half months. Some of us will be playing Overdrive in off-season competitions for the rest of the calendar year.

I think the trailing string idea is a very creative way to give the drivers a little legal slack and make them less likely to draw a penalty by accident. I also think it's a crutch, but that doesn't make it any less admirable.

[jgannon]

Originally Posted by Bongle

Nobody will EVER break <G22> intentionally. Ever. Period. There is zero incentive to do so. There is nothing you can accomplish by breaking <G22> intentionally that will actually result in you scoring 10 points

Not true at all. It has been reported as happening at multiple events, and I saw it in person at Buckeye. Teams have broken <G22> to free their alliance partners from their entanglement with the overpass. Having another robot able to play with you for an additional minute can (and should) net you far more than ten points, and I've seen very smart teams realize this and take the penalty.

[seanwitte]

I haven't seen anyone take the Wallace approach and solve this with technology. As an example, you could also use retro-reflective IR sensors to look for the lines and keep track of your proximity to them. You can mount them off-vertical to give you the ability to "see" the line from a few inches away. With a little programming magic I can think of a few novel applications:

1) Flash an OI LED when you've completely crossed a line and are still within sensing distance of it. The flashing LED means "don't drive backwards!"
2) Write a dashboard app to bark at the driver when there is a danger of violating the <G22> rule.
3) Have a little stop sign pop up on the robot when you're over the line, then pop down when you've crossed. When you see the sign go down you know not to back up.
4) Prevent the robot from moving if the movement will cause a <G22> penalty

Adding one sensor to each corner of the robot would be sufficient. Assuming you're normally driving around in the forward direction you can derive the state model for the sensors.

[Alan Anderson]

Originally Posted by Bongle

Nobody will EVER break <G22> intentionally. Ever. Period. There is zero incentive to do so. There is nothing you can accomplish by breaking <G22> intentionally that will actually result in you scoring 10 points (or preventing your opponent from scoring 10 points). Complaining that <G22> only catches people who broke it unintentionally is stating the obvious. Nobody would break <G22> intentionally, doing so would guarantee a net loss in points.

There are occasions where there is an incentive to violate <G22>.

I've seen multiple teams drive backwards on purpose. They do it to try to free an alliance partner that's gotten hung up on the overpass. Risking a ten point penalty is worth it if you make another robot available for scoring points during the rest of the match.

It's also possible to deprive your opponents of twelve points by knocking their trackball backwards off their side of the overpass just before the buzzer. It's a net gain even if you draw a ten point penalty in the process.

[Brad Voracek]

Originally Posted by Bongle

Nobody will EVER break <G22> intentionally. Ever. Period. There is zero incentive to do so. There is nothing you can accomplish by breaking <G22> intentionally that will actually result in you scoring 10 points (or preventing your opponent from scoring 10 points). Complaining that <G22> only catches people who broke it unintentionally is stating the obvious. Nobody would break <G22> intentionally, doing so would guarantee a net loss in points.

Definitely not true. One match specifically in Los Angeles, I, knowingly got the ten point penalty to knock a trackball off the overpass -backwards-, with there not being enough time to do a full lap. The only way our robot can do this is if it drives over the line a little, sadly. However it gave us a two point swing.. not nearly enough to win us that match (against 330! ) But it was two points none the less.

[Madison]

In Tacoma, our alliance partner was caught on the overpass with their wheels in the air. We knowingly violated <G22> to help get them loose. If we hadn't done that, we'd have lost the match.

[GaryVoshol]

Originally Posted by 65_Xero_Huskie

Yea. It SHOULD be no problem.
But there have been times, not gonna specify, when refs have missed giant balls going over 6ft in the air over an overpass 2 times in 5 seconds. So i think the string would be very hard for some to see and people could get penalties for trying this type of thing.

Mat, this is the 2nd time you have mentioned this, the other being here http://www.chiefdelphi.com/forums/sh...671#post729671 where you did "specify". If you have conclusive evidence of missed hurdles should have been counted, please show it. Not every time the ball goes above the Overpass is it a hurdle. It could have hit the originating robot on the way down. Or the Trackball might have previously been scored, and had not yet crossed the other finish line, so it was ineligible to score again.

[Bongle]

Oops, I forgot the endgame and freeing people from the overpass, thanks for the corrections.

Still, for the majority of tele-operated period, there aren't any strong incentives to break it. Robots don't get immobilized by the overpass too often (once every 3-4 games maybe), and the trackball-knocking only happens in the last 20-25 seconds of the match. So when thinking only about points in time when I'm correct, then my statement was right! ...

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On topic, I'm very conflicted about whether this is lawyering or not. The intent of G22 is to promote circular play. Having a string on your robot, while it is definitely using a loophole in the rules, doesn't break the intent of G22, as you'll still be restricted to circular play. However, using a string comes only as a very to-the-letter interpretation of the rule.

[JesseK]

Or the Trackball might have previously been scored, and had not yet crossed the other finish line, so it was ineligible to score again.

This is the key to one of the best defensive strategies this year, so I'm more inclined to say this was the case. It's very difficult for the crowd to discern whether or not a trackball is eligible to be scored again.

I'd say the only way a ref would miss the string (or G22 penalty) is if the trackball is coming right for them and they have to move for a second. In all of the 100's of matches I watched this weekend, that happened only a few times. Most every other time you could see the little red or blue flag go up indicating the ref was definitely watching.

[Stephen Kowski]

Originally Posted by Alan Anderson

I think the trailing string idea is a very creative way to give the drivers a little legal slack and make them less likely to draw a penalty by accident.

You'd think so, but to the contrary a team at the palmetto tried this very string idea. These strings were the direct and only cause of many of their penalties. I personally would stick to no strings if I were most teams. Good luck and if you do have string, when you get into traffic at the corners of the field I wouldn't move a whole lot (especially spinning in place).

[proegssilb]

Originally Posted by Stephen Kowski

You'd think so, but to the contrary a team at the palmetto tried this very string idea. These strings were the direct and only cause of many of their penalties. I personally would stick to no strings if I were most teams. Good luck and if you do have string, when you get into traffic at the corners of the field I wouldn't move a whole lot (especially spinning in place).

Do you remember anything else about that team? Or maybe what times they played? I'd like to see what exactly this team was doing when they got the penalty.