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Is playing "defense" a legitimate strategy?

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  • Is playing "defense" a legitimate strategy?

    We are a brand new team and would like to know how much a pure defensive strategy is regarded. It would seem to violate the spirit of gracious professionalism. Is it politely ignored or considered a valid part of the game? If your robot wasn't very good at placing rings, it might help the alliance win.

    How much should we plan for other day teams using defensive strategies?

    TIA

    Neil
    _____________________________________
    Co-Coach - Team 6111
    Houston, Texas

  • #2
    My personal take is that defence is very much a legitamate strategy. While my team is transitioning to an offensive strategy as our ring mechanisms improve, our early matches were entirely defensive. Besides a couple of dirty looks when we successfully block an opponent from placing the autonomous ring, this strategy works fairly well.

    Now, be careful with this. Alliance captains prefer offensive robots to defensive robots most of the time, and offensive robots will always end up with more ranking points at the end of the day.

    That said, I met a couple of teams at the Get Over It world champoinship that were purely defensive robots, so I guess anything goes.

    As for preparing for defensive opponents, make sure that your mechanisms will not break when the robot is hit (translation: don't build mission critical parts with vanilla LEGOs). Also, make sure whatever rings you have will not fall out when jostled, and try to avoid a top-heavy bot that will tip over. An autonomous program that corrects for collisions would be incredible too, but I have never seen it done or been able to make it work.

    Good luck!
    FTC Team 4508
    E=MC Squirreled
    Website: emcsquirreled.github.com
    Github Repo: www.github.com/emcsquirreled/FTC-2012
    Lead Programmer and Electronics

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    • #3
      It would seem to violate the spirit of gracious professionalism.
      It is entirely possible to defend and be gracious. The key is to know when to stop; don't break your opponent's robot, and don't abuse the rules.

      Pure defense, as a strategy, isn't very desirable. As an alliance captain, I would rather pick a robot that has the potential to score rather than one which has no ability to score. That being said, defense is extremely important. When you're in a match where you know you can't outscore the opponent, you need to make sure someone on your alliance defends enough to put the match in your favor. If your opponent can score 360 points while you can score 100, don't let them score more than 70 points.

      An autonomous program that corrects for collisions
      Any autonomous that uses the gyro to maintain a heading will be pretty resistant to collisions, since it can correct for them.
      Max Bareiss

      FTC #248 Fatal Error (2009-2013)
      FRC #3142 Aperture (2009-2012)
      FRC #1302 Team Lionheart (2012-2013)
      ZRHS #89 Team Kühlschrank (2011-2013)
      ZRAC #40 Catcher in the Skye (2012)
      ISR 12: Umptysquatch 6
      Rowan University Baja SAE

      And mentoring for life.
      --
      11 seasons of FIRST in 6 years, as a student. Many more as a mentor.

      Comment


      • #4
        When you are fairly good on offense, and then you are thoroughly well defended against in a match and unable to score much or nothing at all, then you come to realize the "legitimacy" of a good defensive preforming robot.

        In our case it was a bot whose only mission was ramp lifting in endgame and defense the rest of the time. Unfortunately for them, their lift approach was also quite easily defended, so their value as a partner was diminished.

        IMO, a bot with a defensive focus must still be able to consistently contribute in at least one other offensive way, in order to expect to go very far into competition.

        -Dick Ledford
        -Dick Ledford, 2010-16 Former Mentor - 3507 Robotheosis

        Comment


        • #5
          Originally posted by Skinkworks View Post
          Any autonomous that uses the gyro to maintain a heading will be pretty resistant to collisions, since it can correct for them.
          Yes, but there is more to autonomous than heading. The trick is detecting the change in position. Even a couple of inches right or left makes a huge difference this year...
          FTC Team 4508
          E=MC Squirreled
          Website: emcsquirreled.github.com
          Github Repo: www.github.com/emcsquirreled/FTC-2012
          Lead Programmer and Electronics

          Comment


          • #6
            Originally posted by emcsquirrled View Post
            Yes, but there is more to autonomous than heading.
            That's what I thought originally, but when we made an autonomous 2 years ago that used the gyro, it remained effective even with opponent anti-autonomous programs hitting our robot. When robots hit each other straight on (not at a corner), there's very little position change happening; it's mostly rotation. Given that, the autonomous won't perform perfectly, but it will work better than you think it would.

            P.S. I now have more posts than GDC Ring Leader. Thank you FTC community for letting me help you this much.
            Max Bareiss

            FTC #248 Fatal Error (2009-2013)
            FRC #3142 Aperture (2009-2012)
            FRC #1302 Team Lionheart (2012-2013)
            ZRHS #89 Team Kühlschrank (2011-2013)
            ZRAC #40 Catcher in the Skye (2012)
            ISR 12: Umptysquatch 6
            Rowan University Baja SAE

            And mentoring for life.
            --
            11 seasons of FIRST in 6 years, as a student. Many more as a mentor.

            Comment


            • #7
              Originally posted by Skinkworks View Post
              I now have more posts than GDC Ring Leader. Thank you FTC community for letting me help you this much.
              You might not know it, but GDC Ring Leader is a pretty competitive guy who will probably view this as a challenge to up his post count - your post made me laugh out loud, Skinkworks!

              Comment


              • #8
                Originally posted by RRLedford View Post
                When you are fairly good on offense, and then you are thoroughly well defended against in a match and unable to score much or nothing at all, then you come to realize the "legitimacy" of a good defensive preforming robot.
                This happened to us in our December qualifier. We had been scoring well all day and made it to the finals, but then in the first match of the finals, both teams on the other alliance were defending against us, and we scored nothing on the rack. The other alliance managed to score one ring on the middle row of the rack, which gave them the victory for that match.

                Originally posted by RRLedford View Post
                IMO, a bot with a defensive focus must still be able to consistently contribute in at least one other offensive way, in order to expect to go very far into competition.
                You have a point there, because our chosen alliance partner for the elimination matches was a purely defensive robot. The servos on their ring gripper had burned out, leaving them as a big defensive box. If they had been able to score, the result of that match might have been different.
                Burning Lights Programming
                FLL Team 341 Brick Chick'N Boys - Programmer (2009-2010)
                FLL Team 263 Brainy Bricks - Programmer (2010-2011)
                FLL Team 5028 Fellowship of the Brick - Youth Mentor (2011-2012)
                FTC Team 6100 Chariots of Fire - Programmer (2012-2013)
                FTC Team 7468 Blue Chariots of Fire - Programmer (2013-2014)
                FTC Team 7468 Blue Chariots of Fire - Mentor/Coach (2014-2017)

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                • #9
                  I would be interested in seeing a robot bypass an anti-autonomous. There are a couple of main ways to do it that I can think of:
                  1. Have a robot that scores so fast that no other team can get in position fast enough to block it
                  2. Write a program smart enough to dead reckon its position, even after collisions, and to also treat other robots as obstacles that can be driven around.
                  3. Build your drivetrain with enough traction/mass to simply shove teams out of the way.
                  4. Have an arm that can reach over other robots.


                  Out of these, 1) seems doable, 2) will probably only be done by the Landroids, 3) is risky and 4) can be done (off the top of my head) only by a diagonal scissor lift.

                  Comment


                  • #10
                    Originally posted by 3608robotics View Post
                    I would be interested in seeing a robot bypass an anti-autonomous. There are a couple of main ways to do it that I can think of:
                    1. Have a robot that scores so fast that no other team can get in position fast enough to block it
                    2. Write a program smart enough to dead reckon its position, even after collisions, and to also treat other robots as obstacles that can be driven around.
                    3. Build your drivetrain with enough traction/mass to simply shove teams out of the way.
                    4. Have an arm that can reach over other robots.


                    Out of these, 1) seems doable, 2) will probably only be done by the Landroids, 3) is risky and 4) can be done (off the top of my head) only by a diagonal scissor lift.
                    #4 Could be done with a linear slide that slides the robot's ring holder over top of another robot to the rack. In fact, I think I read something about a team that had that somewhere, maybe even on this forum.
                    Burning Lights Programming
                    FLL Team 341 Brick Chick'N Boys - Programmer (2009-2010)
                    FLL Team 263 Brainy Bricks - Programmer (2010-2011)
                    FLL Team 5028 Fellowship of the Brick - Youth Mentor (2011-2012)
                    FTC Team 6100 Chariots of Fire - Programmer (2012-2013)
                    FTC Team 7468 Blue Chariots of Fire - Programmer (2013-2014)
                    FTC Team 7468 Blue Chariots of Fire - Mentor/Coach (2014-2017)

                    Comment


                    • #11
                      That would be a great addition to a robot. Kind of like what this robot has, but even more reach: http://www.youtube.com/watch?v=gEDrJVwubQY

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                      • #12
                        And then... there's this:

                        http://www.youtube.com/watch?v=DiGYphcWbcI

                        Comment


                        • #13
                          Yep, that's the robot I was thinking of then I wrote point #4.

                          Comment


                          • #14
                            I would be interested in seeing a robot bypass an anti-autonomous.
                            Another option in your list would be to quickly write an autonomous to counter your opponent's anti-autonomous: an anti-anti-autonomous. Useful in semirare cases (My team has done it before).

                            3. Build your drivetrain with enough traction/mass to simply shove teams out of the way.
                            3) is risky
                            Why is this risky? This is basically our strategy this year, and it seems to be working really well. We have one motor per wheel geared down 3:2 and the robot weighs 30 pounds. Very few robots can push us.
                            Max Bareiss

                            FTC #248 Fatal Error (2009-2013)
                            FRC #3142 Aperture (2009-2012)
                            FRC #1302 Team Lionheart (2012-2013)
                            ZRHS #89 Team Kühlschrank (2011-2013)
                            ZRAC #40 Catcher in the Skye (2012)
                            ISR 12: Umptysquatch 6
                            Rowan University Baja SAE

                            And mentoring for life.
                            --
                            11 seasons of FIRST in 6 years, as a student. Many more as a mentor.

                            Comment


                            • #15
                              Originally posted by Skinkworks View Post
                              Another option in your list would be to quickly write an autonomous to counter your opponent's anti-autonomous: an anti-anti-autonomous. Useful in semirare cases (My team has done it before).
                              Funny story: at a Georgia qualifier during Hotshot, our team was pitted against another that had an extremely effective autonomous program. Right before the beginning of the match, we wrote a silly "drive forward" program, which rammed (and pinned) the other robot during the autonomous period. The crowd hated it, but it's perfectly legal in autonomous.

                              I wonder whether teams have tried using cameras and image processing algorithms to navigate during autonomous.

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