How do you win with defense?


Given the theoretical ability of one strong offensive robot with limited alliance partner assistance to complete a rocket in a qual match, why not just have your two partners spend most of their time keeping a potential opponent defender out of your way?


(Concerning Endgame) As I read the rules, if your alliance can get one Robot on HAB Level 3 and one Robot on HAB Level 2 or 1, the third robot can be left to block the other team from getting to their HAB. You get +1 RP and they don’t get the HAB RP. If there’s anything wrong with that logic, please let me know.


I was talking to someone last night, and commented that THIS is the game mechanic that the GDC should have gone for in 2015. Design the game so that defense CAN be played, but minimize the advantage of doing so as much as possible. It’s a 3v0+3v0, with defense allowed.

As far as how you win with defense, you’ll want to play opportunity defense. I’m over by my rocket and just dropped off a Hatch Cover, and you’re coming in for a score and I have nobody on your side, you. are. getting. hit. I don’t have to hit you very hard, I just have to disrupt you for a few seconds. And for most teams, a quick hard hit will disrupt for AT LEAST a few seconds.

However… I expect that by Finals, most teams will have figured out how to play defense. Remember what wins Championships, folks (except in 2001 and 2015).


This would be somewhat difficult to do given the limited space.

The bots running the screen would have to remain vigilant, doing nothing for the the whole match. Alternatively, they could react once a defender went after the main bot. This reaction could put all 3 robots in the same area of the field, at which point 1 defender ties up all 3 robots together.

I’m not saying it isn’t possible. Yet in my experience with screens in FRC, this year they are somewhat impractical.


Stop trying to convince us not to defend against you, Paul


I agree it’s a bit impractical, but still an interesting idea to think about.

Thinking back, I do specifically recall instances from 2014 where robots with strong drivetrains would find themselves playing counter-defense on opponents while their partners shot. Watch 3467 in the video below - whenever they aren’t inbounding/trussing, they’re running cover to make sure 125 has an easy time lining up at the low goals to shoot high.


I personally think that defense is going to be big factor in deciding games. In some other post somebody did the calculation which gives us 5/8" tolerance on each side when placing hatches which can take some time. Even using a camera or omni wheels, teams will be quite vulnerable to being hit during that time allowing less capable teams to take out powerhouse ones unless you get a body block from an alliance member.


You can’t tip over robots intentionally. We thought about that but it’s covered in the manual. See G19.


I would have to disagree with that… with how tight the alignment tolerances are on targets this year, giving people a few bumps could delay them by a huge amount of time.


Defense is either blocking access to an area, or slowing up opponents robots movements. Defense is almost always a driver skill centric behavior, mechanisms rarely matter much.

Assume that 3 robots have 15 seconds cycles times and thus can place 10 pieces each getting 75 points. Lets assume that defense can add 3 seconds time to each drive them 62 points would be scored. A difference of 13 points ( 3 balls and 2 hatches) if the robot can’t cycle faster than 30 seconds his defense would be more value than his offensive point scoring.

However if he prevent robots from successful place balls and hatches on one aisle of the field than he would cut the score closer to 50 points. Which is only useful if the team is likely to score over 50 points on cargo and hatches.

Defense doesn’t win you game, but it may prevent the other side from scoring enough point to win.


To me, it feels like this game is very much about the efficiency of scoring, and figuring out how to score as much of your maximum “cap”/point potential as possible.

Though it is in some cases impractical, dedicated defense can change your score advantage over your opponent in a few ways.

  • Lower the cap of your opponent (Stealing Cargo from across the field and hoarding them in your Cargo Ship, such that they cannot finish all Hatch/Cargo pairings)
  • Lower the efficiency of your opponent (Physically preventing access to/placement of scoring elements)

Of these, I think the latter is going to see a lot more usage. For cases in which you and your opponent are tied in theoretical Alliance efficiency, ramming opponents as you come out of a scoring cycle is helpful, as you (likely) lose less time than they do trying to continue with your cycles.
In cases where your alliance’s efficiency is already significantly lower than your opponents, you could have someone with low contribution physically impede ball/hatch scoring on a rocket and bring your opponents to about your level of efficiency.

Quite honestly, my teams are going to be more focused on building ourselves up and getting that rocket RP in Quals than trying to tear you down and keep you from earning yours - unless, of course, we see that strategy as the one winning us the match. I’d expect to see something similar come out of most regional play, but I do think defense has its place, even (if not especially) on Einstein.


Blockquote The human player station is completely contained within the HAB ZONE, and so parking directly in that area would generate a foul when a robot came to retrieve a game piece. (G13, also see blue box under G7)

It’s only a foul if their bumpers are entirely within the HAB zone. A good driver could move around in the area between the low platform and the wall and make it very difficult to get past them to the loading station, and get out of the way if/when a robot comes over the platform with its bumpers fully within the zone.


Rule G5 says you can’t mess with an opponent’s SCORED piece, so no removing of hatches. If a hatch is pre-loaded its considered null and not scored…so technically maybe?? I am trying to extremely bend the wording to play some defense and spice up the game play lol


I (mostly) don’t see the logic in playing defense in quals. Every year since the “game” in 2015 people have talked about the current years’ version of the “Noodle Agreement”. For those who weren’t around for that “game”, the Noodle Agreement basically stated that neither alliance would throw pool noodles (which scored points in a way) to the other side of the field. The pool noodles would get in the way of the opposing alliance and make it more challenging to rank high. So it was mutually beneficial to not throw noodles, and not have noodles thrown at you.

Similarly this year (more than any year since 2015 in my opinion) teams are incentivized to form an agreement to not mess with each other so that both alliances can score the RP. Logic being that you spend time finishing your own Rocket RP rather than prevent the opponent from missing their RP.

Where this “agreement” breaks down a bit is that a win is 2 RP compared with just 1 RP for the Rocket. The weaker cycling/scoring alliance has incentive to disrupt the stronger alliance to gain 2 RP’s rather than 1 RP. This is especially true when the opposing alliance has a single strong cycling robot that can may be significantly slowed down by a much weaker cycling robot on the weaker alliance. On the flip side, if you’re completely outgunned and you know it… you’re better off getting 1 RP than 0 RP. So the agreement works in that situation as well.

I suspect that defense will be extremely prevelent in the playoffs. I feel like the 24th best cycler at an event (at least in my region) will be able to slow the opposing alliance down more than they can contribute positively.


True. Disrupting access to the feeding station is definitely a way to slow down the opposing alliance. I just wanted to note, in response to the post I quoted, that you weren’t allowed to just sit in front of the station in the “tight” area. You would have to play a more active defense, as you described. If the opposing robot is stronger, they would just push you backwards until they were completely in the hab zone and you would get a penalty. If they couldn’t do that, they would have to skate past you on the platform area or run past you to the side until they broke into the zone. Skillful driving and the right drive train could still cause a significant delay to the team trying to load a piece, but it isn’t as simple as sitting in front of the human player station.

One element that makes defense viable in some circumstances this year is that it will likely take some seconds to align yourself for precise delivery, while it will take very little force to disrupt you from precise delivery. A simple knock out of alignment while trying to line up on that white gaffer’s tape, and you might lose several seconds.

Definitely in the playoffs when the last pick of that serpentine draft is facing off against a very high scoring robot, it seems likely there will be cases where that robot will be more effective as a defender.

The Right Drive Train?

You can slow progress, a wee bit, towards getting the rocket ship ranking point using defense. Get in the way of robots working on one of the rocket ships then when the other rocket ship is almost done go guard the other rocket ship. Like Paul said you can slow down and maybe prevent that RP but not easily slow down point accumulation. Building dedicated defense bots for this game is not what the GDC intended.


I agree with all of the other users talking about slowing the opposing alliance’s progress. How I believe defense could play a role in matches is it creates an obstacle. How I understood the rule book, defense this year is supposed to create a distraction for the other drivers. When scoring, not only do you have to avoid colliding with your team mates, now there is a robot purposely trying to hit you. This defense bot could be targeted on the opposing alliance’s strongest scoring bot, either slowing them down or shutting them down completely (like not letting them score, not like actually shutting them off). Though I do not believe that defense = win, I do believe that it could play a role in securing the win.


That was not technically the noodle agreement or at least not how it got its name originally. Before a rule change all noodles were the same, so both sides could just drop their noodles infront of the drivers station and both sides would get 40 points (4 per noodle). This only worked because 2015 was not really played red vs blue but average score. Because FIRST did not like this they added the colored tape so noodles had to come from the other side of the field to score.


During Sandstorm you’re not allowed to cross to the other side of the field


This is rarely a winning move. It is highly situational, and carries a number of pitfalls. Not the least of which is accidentally touching them while they are in the Hab area, giving them free climbs.

A very sharp driver may be able to pull this off once in a great while, but as a routine strategy it doesn’t have legs.