YMTC: Defensive Strategies

OK so we are all aware that there is going to be lots of interaction this year and pushing, bumping, etc… is to be expected and you should have had your robot designed to be able to take a good amount of abuse.

Now the question: at what point does playing defense go past what was intended by the game creators and at what point level should it be penalized. After watching the webcasts for the past 2 weeks I have seen many times where a robot goes out and defends the opposite side of the field while the partners score on the opposite end of the field. Works pretty well I must say, definitely a valid strategy.

But what about teams that go out and back up and hit a robot then back up and hit a robot at high speed even continuing after getting repeated penalties for excessive ramming, a tactic that must be intended to do damage to the other robots. What should be the rule if they do it every match and continue to get similar penalties.

I would think at some point FIRST should give them a final warning then if the condition persists disqualify the team. Remember, this is different from interaction with other robots, this is backing up and ramming repeatedly.

Say your the head ref, you make the call.

Rule <G25> spells out examples of violations that are both within, and beyond, the spirit of the game. The rule also clearly gives referees the authority to remove a team from the enitre competition event if a team repeatedly violates the rule. If a team displays repeated agressive play, and continues after warnings from the referees, they can and should be removed from the competition.


Using a sports analogies: During a basketball game, an opposite player (RED) is comes down the court with the ball (tetra). He (RED robot) attempts to score a 3-pointer. You (BLUE robot) intersects him and smashes him on the side of the head (hitting high), he (RED) continues to aim his shoot; you smash him again, and again and again.
Sounds like a DQ?

If some team keeps breaking rule <G25> in the same match, I would assume that the refs would disable that robot for the remander of the match. The refs are good about calling these rules so I don’t think you need to worry about getting too damaged.

GO 1403!!!

apperently, the head ref at ypsi didnt like wedges…

My reasoning for the question is that the rulings at different regionals has been very different.

I spoke with teams at Great Lakes and they were warned immediately that any sort of high speed ramming would not be allowed and the repeat offenders would be DQ’d possibly for the entire event if it continued. At other regionals such as Pittsburgh it was allowed to continue over and over with penalties to the offending teams but nothing any higher than that resulting in significant damage to many robots.

I would ask FIRST to talk about it next ref meeting so that the regionals are scored and ruled the same. Also I would ask teams (Coaches and Mentors) that are using a defensive strategy to also consider the damage that high speed ramming causes and not use it as a strategy. Again ‘rubbins racing’ but if this is now battlebots, we didn’t bring the right robot this year, I fully expected the refs to call some of the matches I watched yet they let the ramming go on.

The way it SHOULD be would be the way defensive fouls are called in basketball. If the defender is moving and interferes with the offensive player, there is a foul called (dq). However, if the defender is planted (feet staying still, player not moving) there is no foul called on the defender in an “incidental” confrontation. I haven’t looked a whole lot at the actual rules, but in the spirit of gracious professionalism, this is the way it should probably be…

Portland was wonderful. There was very little intentional high-speed ramming and penalties rarely seemed to change the outcome of matches (even though we lost a match 26-1 when a partner racked up 40 points in penalties but I’m not bitter really I’m not I understand these things happen even though we scored 22 of our team’s 41 points and capped once in our opponent’s end row breaking up a row and deserved to win and we never drew a single penalty in the whole tournament but I’m better now that the doctors have given me these nice pink pills to take and they were chosen for a finals alliance and we weren’t).

Seriously. Except for some problems with the field system, the whole experience was a dream, with the referees warning some drivers (including ours) about excessive ramming early on Friday. Despite my ranting above, the referees and judges made sure that the rules were applied fairly, firmly, reasonably and consistently.

There’s definetely a difference between repeated ramming with the intent to deal damage and backing up then moving forward again to avoid the ten second pinning penalty. I would think it would come down to the ref’s opinion on what the intent is, whether to destroy or to pin for a few seconds.
Another thing, FIRST is not basketball. Contact is perfectly legal, and using your robot’s superior torque to push another robot away from a goal is also perfectly legal. There are some bots who do this well, and there are other bots who are high speed, low torque and all they can do is hope to ram into a bot enough to keep it from scoring. The first type is perfectly valid, the second has no place in Gracious Profesionallism.

Defense can be played as affectively using placement rather than pushing or ramming. The rules clearly define pinning so everyone knows that you must back off 3 ft - it isn’t intended to provide enough space to repeatedly smash into the opponents.
Interaction is expected when remote control mechanism are confined to a closed area and the objective is both offensive (scoring) and defensive (not allowing them to score) depending on the situation, the strategy, and the robots capabilities.
Defense as a strategy is fine and necessary to make a good game. How the defensive strategy is executed is what is in question. Avoid ambiguous terms in definitions, like “intent” - the obvious is obvious, but the less than obvious is left to human judgement. When leaving the interpretation to people, expect differences based on opinions and experiences. What is high speed ramming to one person may not be High speed ramming to another. Rules with measurable boundaries far exceed those without. Out of bounds includes touching the line, Straddling the line means one wheel on either side, 120 lbs can be measured.
I would suggest, during the driver meeting the folks clearly define the acceptable behavior when playing defense, not the resultant action for being penalized.
Make it clear, use examples with the drivers so they can related to it - make sure everyone understands and is provide the opportunity to ask questions for clarification without being embarassed. Each team should be required to send the coach and driver to a seperate quiet room on Thursday to discuss these issues and make sure they understand the rules.
This year more than ever, the alliance partners impact more than the outcome of a single match - they also can impact the seeding of their partners. I would hope that everyone cared enough not to either wreck another teams robot nor mess up their alliance partners of seeding - just because they were trying to show off their ability to defend in hopes of being selected later by a team looking for an enforcer (defense by brute)

see i have to disagree with you on this. i think teams should be able to stop an offensive robot. i think the ramming rule a little harsh because teams should be building their robot for a little abuse, but a full power ram should not be able to fly. i do not agree with the tipping rule. the head ref at ypsi told us if we picked a robot up even an inch, we would be penalized. i understand that tipping is against gracious professionalism, which is why when a robot started to tip, we backed off…but it makes me wonder why the rules are so strict this year

I think that we all need to consider very carefully before asking the refs to call more penaltys. Please don’t get me wrong. I absolutely do not want to damage another team’s robot. I will do everything I can to ensure that none of my teammates intentionally damage another team’s robot. However, my number one priority is the sucess of the FIRST mission. I feel that the only way to make the kind of impact on society that we all want to make is to increase the depth of the FIRST Robotics Competition audience. Robots to robot interaction while fighting to score is very exciting to watch. FIRST needs this.

Team Phoenix - 703 will abide by whatever rules on defensive play that the refs decide on, but my vote is “let um fight it out” Let’s get this show on ESPN.

Matt B.

I agree. We certainly don’t want to damage anyone’s robot (at least nothing serious) but the more rules and penalties there are, the less creative teams can be. If we all end up doing the same things because of limits on strategies caused by fear of penalties, the game will be boring and predictable.

Having a robot that got three wheels broken off at Sacramento, two
in rapid succession with a multiple attempts at the third as we could still
“offensively” move to score, I would like to suggest that if high speed
ramming is allowed, that we also be allowed to build and field the
perfect energy absorbing bumper.

It goes as follows:
Have a metal plate outside the wheels, but within the legal footprint.
The plate is mounted on shafts that go through bushings in the frame.
The shaft contacts the handle end of a 10 pound sledge hammer on a pivot
so that when the plate is struck at high speed, the kinetic energy of the
impact is converted to kinetic energy in the hammer that slams down
vertically on the robot that struck at high speed. The plate is on the
side where it could not be employed offensively, and where it would
protect the wheels. Any robot that tries to get themselves a wheel,
or two, had better be well amored from above. A simple push does not
impart any energy to the hammer that is otherwise kept in place with bungies…

This really looks like battle bots, but any rational person would say
that a robot that is slamming to produce damage is getting their due.
Legal? You get really unhappy when a team slams a high speed only
for the purpose of breaking wheels off. It has no place in FIRST robotics.

Some teams are very good at defense. Our robot was built to cap the goals and we can do 3 to 4 caps per match but we found out that defense is our strength. Our main driver is very good about not ramming robots. He goes slow until he is touching them and then pushes them. You cannot discourage defense because then it would be too simple of a game. If we see you trying to cap a goal that we don’t want you to cap, we’re going to go over to you and push you. I think if there is repeated contact then it is maliscious. If there is 1 time where contact occurs and then it continues, that’s just good defense. Our strength is defense any we might be able to defend any robot in the competition so my opinion is probably weighted. But when it comes down to it, ramming is wrong, pushing is good…

…and kinda fun :smiley: .

Dr. Brooks
Do you really believe that the other team was trying to break your robot?

If they indeed were this is a very sad time in FIRST robotics.

I admit that I am perenially nieve, but I truly believe that most of these situations are young people who get a little excited about trying to keep an opposing robot away from scoring position. If they cannot push you steady state the natural (and wrong) reaction is to use an impact. It is our job as coaches to be on gaurd against that.

I don’t want to believe that any team in FIRST would intentionally break another robot to win a match.

The only problem with that analogy is that in basketball you can steal the ball (tetra) as which you cannot do here. Also, in basketball you are stopped if you do not make the ball available to the opposing player by dribbling. I like a better analogy of soccer. Stay between the goal and the ball (tetra). Nudging and side contact are to be had but nothing to trip the other player up. And if you are blocking a tetra then you should be contacting it. For example, at the Arizona regional team 555 has a low robot with an arm that has a ball on the end that they use to keep a tetra from being capped. At the Arizona Regionals I will be happy to report that through gracious professionalism I didn’t see any intentional robot knock overs even though the possibility existed many times with a cappers arm connected to the top of the goal. There were a couple accidental knock overs, however. The few defensive robots made the matches exciting at our regional. It was a good break from the “I can cap faster than you…” game not to mention that they were seeded well. I predict the nat. champ alliance will have at least one defender.

I am not saying turn FIRST into battlebots. I think teams need to take defense into concideration when building a robot. They need to be well protected, the electronics well protected, and have no loose hoses/wires of any type. Also, alot of top heavy robots this year with these monsterous arms. I was amazed to see how high some of the teams actualy got. The rules state “No pushing high”, but if you push low they tip. I feel bad when other robots get tipped over or destroyed because i know how hard teams work to build, but sports are not about offense. How many football teams do you see walk on the field and not play defense(besides the detroit lions :smiley: )???

Teams need to play defense and push other robots around. Intentional destruction should not be accepted. Alot of the parents and on-lookers do not want to see a bunch of robots scoring, they want to see some contact. It makes the game fun.

You are incorrect in this point. I manipulate for our team and I stole a tetra from another robot when they were about to cap. You just have to be careful that you do no tip them or descore the tetra. Oh man taking that tetra was by far the best maneuver I’ve made with our arms the past 2 years. And the most fun.

It seems that we sometimes use the word “defense” as a code word for “ramming”. I would like to offer a number of other potential defensive tactics where pushing is not required:

  1. Removing a tetra from an opponent’s arm before they can cap.
  2. Blocking your opponent from reaching their human or auto loading zone
  3. Capping a goal(s) in your opponents’ home row
  4. Pretending to cap in your opponents’ home row to draw them out
  5. Extending your arm over the goal to keep it from being capped

Would these actions be viewed as non-GP, or just good strategic moves?