Defensive Robots/Strategies?

[garyjune]

Considering the shuttling and the importance of cycle times in this year's game, how effective would defensive strategies/robots be?
Would it be a better idea to defend against gear or ball scoring robots?
What design elements/components would increase a robot's defensive capability?
Would a hybrid gear + defensive robot be viable?
What would defense this game look like?

[NerdyCharmax]

I think that to be an effective defense bot all that you really have to do is go to the opposing alliance's launch pad and clog up some of the narrower passages between the drive station and the airship. Then there is also of course the ability to severely lengthen your opponent's cycle time just by being in the way and forcing them to adjust their path in the neutral zone. Make sure that you check up on the rules before pursuing any aggressive defensive strategies.

[MARS_James]

Originally Posted by garyjune

Considering the shuttling and the importance of cycle times in this year's game, how effective would defensive strategies/robots be?

Very, even more so than last year

Originally Posted by garyjune

Would it be a better idea to defend against gear or ball scoring robots?

Why not both? But if I am being honest Gear robots are easier to defend against since ball scoring robots will be able to put themselves against a wall or in a safe zone and just shoot over you or between hits.

Originally Posted by garyjune

What design elements/components would increase a robot's defensive capability?

Powerful drivetrain, 6 cim, preferably two speeds to chase down and pin. Low ground clearance so as not to accidentally acquire game pieces. Max height for your size box. Low center of gravity. High traction wheels.

Originally Posted by garyjune

Would a hybrid gear + defensive robot be viable?

I think designing a robot to do both is a good idea, but during an actual match post Auto, it is better to focus on one task or the other.

Originally Posted by garyjune

What would defense this game look like?

So post Autonomous head to the area between your airship and their feeder station push/pin a robot heading to retrieve a gear till you either are nearing their safe zone or you need to break the pin. Wait for them to retrieve the gear.

They will either A)need to go around the air ship to not deal with you or B)try to get by you

If A: Go diagonally towards their desired path they will either: 1) Redirect and play chicken, 2) Run into you and now you have a pushing match heading towards your safe zone so they are risking a penalty 3) You pin them for a legal pin

If B: Don't let them by turning it into a pushing match or pinning them legally

Either they get by you or you spend the entire match shutting them down if it is the latter congratulations, you did your job and will be on someones pick list for effective defense if not.

Once they get into the area to score the gear that is not a safe zone, be as disruptive as possible and you will either slow them down or make them drop the gear.

Either they score the gear or they don't. If the latter once again congratulations, you did your job and will be on someones pick list for defense if not repeat the steps listed above.


If someone is making you waste this much time the whole match than there is no way you are cycling fast enough to engage the rotors by themselves.

[Lil' Lavery]

The mandatory feature required of all teams attempting to play shutdown defense near the opponent's airship will be a way to solve the visibility challenges presented by the airships.

[Brian Maher]

Originally Posted by MARS_James

I think designing a robot to do both is a good idea, but during an actual match post Auto, it is better to focus on one task or the other.

I don't agree with the boldfaced text. Granted, neither of us will know with certainty until the game is played, but consider this scenario:

Say Robots A, B, and C are on an alliance. Robots A and B can score a total of five gears. Robot C can place up to three gears and play defense. If A and B place their five gears (plus the free gear), the alliance engages two rotors (80 points). If A, B, and C place their maximum eight gears, the alliance engages three rotors (120 points). However, if A and B place their five gears and C places one gear then plays defense, the alliance still engages three rotors (still 120 points) plus they gain whatever havoc C wreaks on their opponents.

[TDav540]

Originally Posted by Brian Maher

I don't agree with this. Granted, neither of us will know with certainty until the game is played, but consider this scenario:

Say Robots A, B, and C are on an alliance. Robots A and B can score a total of five gears. Robot C can place up to three gears and play defense. If A and B place their five gears (plus the free gear), the alliance engages two rotors (80 points). If A, B, and C place their maximum eight gears, the alliance engages three rotors (120 points). However, if A and B place their five gears and C places one gear then plays defense, the alliance still engages three rotors (still 120 points) plus they gain whatever havoc C wreaks on their opponents.

+1 to Brian here. It's very alliance and match dependent.

[MARS_James]

Originally Posted by Brian Maher

I don't agree with the boldfaced text. Granted, neither of us will know with certainty until the game is played, but consider this scenario:

Say Robots A, B, and C are on an alliance. Robots A and B can score a total of five gears. Robot C can place up to three gears and play defense. If A and B place their five gears (plus the free gear), the alliance engages two rotors (80 points). If A, B, and C place their maximum eight gears, the alliance engages three rotors (120 points). However, if A and B place their five gears and C places one gear then plays defense, the alliance still engages three rotors (still 120 points) plus they gain whatever havoc C wreaks on their opponents.

Sorry i failed to elaborate on this my point was more so, if your tasked with playing defense, getting a gear is not an effective strategy. If your tasked with getting gears, playing defense is not an effective strategy, however if your task is put up x gears what you do after/inbetween is up to you but get those x gears.

[SMR Vault]

Originally Posted by garyjune

Considering the shuttling and the importance of cycle times in this year's game, how effective would defensive strategies/robots be?
Would it be a better idea to defend against gear or ball scoring robots?
What design elements/components would increase a robot's defensive capability?
Would a hybrid gear + defensive robot be viable?
What would defense this game look like?

There are 2 core defensive strategies (from a general design standpoint) to consider based on the 2 volume constraints:

1) Vertical Defense- Use your robot to block potential fuel shots by choosing to build using the volume option with a focus on height (30 in. by 32 in. by 36 in. tall (~76 cm by 81 cm by 91 cm tall)).
This option is difficult to pursue for 2 reasons:

• Most balls shot in the high efficiency goal most likely follow a steep trajectory that your 36 in. height limit may not be able to block.

• If your robot is able to block shots, getting your robot in position to block will be quite difficult, and will require manueverability that our robots may not be capable of. Well trained drivers are advised for this strategy in particular.

2) Horizontal Defense- Use your robot to effectively pin opponents by selecting the volume option with a focus on width (36 in. by 40 in. by 24 in. tall (~91 cm by 101 cm by 60 cm tall)).

• The greater width of this design allows for greater blockage in tight spaces. Here are the rules for pinning:

G11.There’s a 5-count on pins. ROBOTS may not pin an opponent’s ROBOT for more than five (5)
seconds. A ROBOT will be considered pinned until the ROBOTS have separated by at least six
(6) feet. The pinning ROBOT(s) must then wait for at least three (3) seconds before attempting to
pin the same ROBOT again. Pinning is transitory through other objects. If the pinned ROBOT
chases the pinning ROBOT upon retreat, the pinning ROBOT will not be penalized, and the pin
will be considered complete.

• This strategy takes a more contact-centered approach to interfering with shots; since shooting into the high efficiency goal will be such a challenge for teams this year, any light interference to a robot setting up for a shot may be enough to cause the opponent to miss. If you take this route, be mindful of the rules regarding contact:

G08. Don’t tear others down to lift yourself up. Strategies aimed at the destruction or inhibition of
ROBOTS via attachment, damage, tipping, entanglements, or deliberately putting a GEAR on an
opponent’s ROBOT are not allowed.

G09. Stay out of other ROBOTS. Initiating deliberate or damaging contact with an opponent ROBOT
on or inside the vertical extension of its FRAME PERIMETER is not allowed.

In terms of contact, both vertical and horizontal builds should be equally effective, but the width of the horizontal should be more effective for pinning.

In regards to height, the distance from the ground to the top of the high efficiency is roughly 27 in. The maximum height for a vertical bot is 36 in. and for a horizontal bot is 24 in. The horizontal bot should semi-effectively block shots into the low efficiency goal, so this is something to consider when picking a strategy.

In summary, your most viable option is probably to pursue interfering with ball-shooting robots. They are easier to throw off, as many teams seem to be implementing safeguards against gears falling off.

[SMR Vault]

We reviewed some core defensive strategies in our video update of weeks 1 & 2, so we recommend your team checks this out to see how other teams are implementing some of these strategies!

https://youtu.be/PJhMr0CW83s

[Edxu]

The field this year has some semblance to Ultimate Ascent's field, with large field objects creating chokepoints. The chokepoints this year are the two corridors where robots can exit their key.

Optimally played defense will make it extremely difficult for boiler-scoring robots to leave the key after their cycle, as IMO, playing defense on intaking robots is more important than defense on scoring robots, as accuracy matters less than volume of fuel fired.

A blue robot shifting between these two positions can significantly disrupt an opponent's cycle time, and even has the potential to entirely lock them out of acquiring new gears or fuel to cycle.

http://imgur.com/a/NA1uK

[kenfox]

Originally Posted by garyjune

Considering the shuttling and the importance of cycle times in this year's game, how effective would defensive strategies/robots be?

Defensive play seems to fit best with a shooting strategy. The first 2 rotors are must-haves, but a shooter can win with 41 pts in fuel if they prevent opponents from getting 4 rotors.

I hope we see a shooter than can put up 40 pts in auton. They'll seed high and should be able to pick a good auton gearbot and another gearbot. That's enough points coming out of auton to win with a pure defense teleop strategy.

In a gearbot vs gearbot race, the first alliance to 4 rotors will have to decide to go full defense or shoot. If they get to 4 rotors with a 4 gear lead, it probably makes sense to go full defense. Or put up a point of fuel just to cover the case of a rotor tie before switching to full defense. An auton fuel dump into the low boiler by a gearbot will be valuable for the same reason.

If an alliance feels they can win in the climb, it may pay to be very defensive as well because climbs can dominate low point games. Strong defense and good clock management will be very hard to play against though it requires more coordination than alliances can normally execute.

It will be fun to watch these matches and see where the meta goes!

Best advice this year (as it is most years) is don't skimp on your drivetrain. Speed and reliability are critical to both offense and defense.

[Raysaran]

Originally Posted by garyjune

Considering the shuttling and the importance of cycle times in this year's game, how effective would defensive strategies/robots be?
Would it be a better idea to defend against gear or ball scoring robots?
What design elements/components would increase a robot's defensive capability?
Would a hybrid gear + defensive robot be viable?
What would defense this game look like?

Playing defense on the return feeder station is probably the best way to go, you get a huge vision advantage and it's a lot harder to see your robot behind their airship.

[Parker Brotman]

Originally Posted by Raysaran

Playing defense on the return feeder station is probably the best way to go, you get a huge vision advantage and it's a lot harder to see your robot behind their airship.

An extremely important thing to note about this is that as per G13, "A ROBOT with any part inside its opponent’s RETRIEVAL ZONE may not contact an opposing ROBOT, regardless of who initiates the contact. Violation: TECH FOUL." You can defend against robots that are near the retrieval zone, but be extremely careful about it because tech fouls aren't fun.

[Parker Brotman]

Originally Posted by garyjune

Considering the shuttling and the importance of cycle times in this year's game, how effective would defensive strategies/robots be?

I agree with everyone else that defense will be a big factor this year. A mostly open field which also has a few chokepoints lends well to defense, as well as the fact that there's only one fully protected zone per alliance.

Originally Posted by garyjune

Would it be a better idea to defend against gear or ball scoring robots?

Either could be good depending on the circumstances of any given match, but generally I'd think defending against gear-delivering robots would be a more effective strategy due to the nature of how gears and fuel are each scored. Fuel is scored in a fluid manner, meaning a team basically sits in front of the boiler and the score steadily ticks upward. Gears on the other hand are scored in an incremental manner, meaning you only get points when your gear total passes what I think of as a "checkpoint." The gap between the final two checkpoints (rotors) is equal to the sum of all previously delivered gears, so if you can keep the opposing alliance down to 11 delivered gears, it's just as good as limiting them to 6 delivered gears, and you're making their last 5 gears completely worthless.

Originally Posted by garyjune

What design elements/components would increase a robot's defensive capability?

Good drivers and a strong drive train.

The more experience your drivers have, the better they will be at all aspects of the game, especially defense. There's something to be said for keeping your design simple and finishing early so that you're drivers (and programmers) get more time with the robot. And the thing about practicing defense is you don't even need a full robot to begin practicing; all you need is a functioning drive train.

Unless you can pull off a more complex drivetrain such as swerve or octocanum, I'd stick with tank drive (as in 6 traction wheels, not treads). This is a very contentious topic, but most people, myself included, would highly advise against using a mecanum drive or an H drive, as the (slightly) increased mobility is outweighed by the fact that they will get pushed around easily by other robots. And if you have well-trained drivers, you should be totally fine with the mobility of a tank drive.

As for the transmission, I like shifting gearboxes. You can have a very low speed which is great for pushing other robots, and you can have a high speed which is good for traversing the field quickly.

Originally Posted by garyjune

Would a hybrid gear + defensive robot be viable?

If your talking about robot design, absolutely. All it takes to build a good defensive bot is a strong drivetrain.

If you're talking about strategy, it could work. If you're confident your alliance can get 3 rotors activated but highly doubtful your alliance could get up to 4, one good use of your time instead of cycling useless gears would be to play defense.

A hybrid fuel + defensive strategy for your robot might be even better though. To pickup a gear requires that you fetch it from a specific location on the field, whereas fuel can be found everywhere. This means that you can both intake fuel and play defense at the same time.

[Alex Cormier]

I am very excited to see how D will play out this year. Can't wait.