Is Defense Finally Viable
 

With only one game piece per alliance, is defense a viable strategy this year?

Will the time spent by the opposing alliance trying to score around a defensive bot outweigh the loss of an offensive bot?

I'm just interested what the CD community thinks.

Re: Is Defense Finally Viable
 

It may be the opposite; defense could become quite hard considering how ugly the rules about possession of a ball are.

Specifically, it can be hard to ensure a given bounce is a deflection and not a launch, or a deflection and not herding. See G12 of the rules for more details about this.

Re: Is Defense Finally Viable
 

That's a very good point. Do you think that being hit by the ball while intentionally blocking the low goal counts as intentionally touching the opponent's ball? Would a team get penalized for that?

Re: Is Defense Finally Viable
 

You are allowed to intentionally touch an opponents ball, just not POSSESS am opponents ball. Thus blocking the low goal is legal, and may be very effective.

I believe that defense this year could very well be powerful, if done right.

Re: Is Defense Finally Viable
 

To clarify, referencing G12:
If you are blocking and the ball hits you, it qualifies as deflecting, and thus not possession.
Repeated hitting of the ball counts as herding though, which is possession.

Re: Is Defense Finally Viable
 

Umm... no. That's not what "intentional" means.

Re: Is Defense Finally Viable
 

With the limitation imposed by Rule R3-D I suppose it will be a matter of the defensive driver's skill versus the effectiveness/speed of the offensive robot's launcher. The only way for the goalie to defend is to quickly strafe to the position that the ball is being launched to in order to stop the ball with it's puny little 6 Dia. inch extension. If the defending robot is quite fast and has a skilled driver, then I'd say they'll have a good chance.

That said, there is still a lot of room in the high goals for the offense to aim at. I think the best way to counteract a good defense is to have a robot that can turn very quickly and then adjust the power of the launcher to account for the different angle.

I think that defense is definitely viable, and more teams should go for it this year. If we had a defensive robot on every alliance, it would make for much more exciting matches than the assembly line business that going for high points would bring.

Re: Is Defense Finally Viable
 

Consider a 5' tall defender up pushing against a high goal shooter. Unless the ball comes out of the shooting robot at 5'+ it can be blocked by the defender.

A quick aggressive defender with a powerful drivetrain can block all but the tallest shooters.

Just another strategy.

also consider a pass advancing robot where a defender pushes up against it such that the pass advancing robot cannot get the ball out of their own robot ...

Defense will be played this year, and (by some) will be played very effectively.

Re: Is Defense Finally Viable
 

I'm thinking defending the top goal is pointless. There's too much area, for too small a blocker. Add to that the rarity of top goal scorers anyways, and you're designing yourself into a pretty small niche.

Best defense is probably locking down the opponent's weakest robot to limit the maximum assists available to them. And really, what else are you going to be doing while you're off the ball? You're either running interference, or you're defending. Defense capability is almost mandatory this year, because you're going to be spending some amount of time not scoring if you're doing the assistance dance. On the other hand, defense only with zero ball handling ability seems like a pretty serious deficit. You're seriously limiting your alliance's scoring ability and flexibility.

Re: Is Defense Finally Viable
 

True, but you might as well design for the top goal anyways. That way you can block the bottom ones as well if you need to.

Re: Is Defense Finally Viable
 

Kevin & E Dawg both made good points. Now it looks like the best way to avoid a defensive rammer is to design your ball launcher/passer to launch out of the top so that the ball doesn't get trapped in your robot.

There are probably more ways to defend effectively; it will be sweet to see what teams comes up with.

Re: Is Defense Finally Viable
 

"G25 ROBOTS on the same ALLIANCE may not blockade the FIELD in an attempt to stop the flow of the MATCH. This
rule has no effect on individual ROBOT-ROBOT interaction.
"

So is blocking passes (rather than pinning the passer) a viable defense... a hot topic in our group this afternoon?

Re: Is Defense Finally Viable
 

My interpretation of that rule is the image of all 3 alliance robots sitting in a row blocking the middle of the field from being passed. The rule is only meant to put a hard restriction on that "strategy." So pinning a passer while they're trying to pass wouldn't be breaking a rule; just don't pin them for more than 5 seconds.

Re: Is Defense Finally Viable
 

Are defending robots allowed to hit the opposing alliance's ball without gaining possession?

Rule G12 prohibits a robot from having possession of an opponent's ball. Does one hit count as herding, and therefore possession?

What if a red robot hits a ball possessed by a blue alliance robot?

Re: Is Defense Finally Viable
 

Herding is repeated hitting; however, launching appears to be simply hitting the ball. So if a red bot hits a ball possessed by a blue alliance bot, it counts as launching.

Deflecting is when the ball hits a bot; herding/launching is when a bot hits the ball. Basically, if the bot did it on purpose, it's possession.

Does this mean that you cannot touch the ball while defending, besides when they fire it at you? This could make defending hard.

Re: Is Defense Finally Viable
 

This is exactly what I was trying to figure out.

I can't imagine possession would be granted simply for hitting the ball though. That would make assists much more easy.

Re: Is Defense Finally Viable
 

I don't think Defense is going to be as easily effective as last year's game.

Re: Is Defense Finally Viable
 

Why do you say that?

Re: Is Defense Finally Viable
 

(emphasis mine) In order to herd, you would have to show continued effort to influence the direction of the ball. Just running past it and bumping it (as long as you're going somewhere) is 100% legal ("bulldozing").

In your second example, it would depend on how the opponent is possessing the ball. If the ball is somehow held inside the frame perimeter, possession should be the least of your worries:
If you're defending against a robot who's method of possession is herding, possibly with an extended mechanism, then the G28 Blue Box comes into effect:
So you can hit their mechanism (without an intent to damage) unpenalized. And as long as you aren't trying to gain possession of their ball, you shouldn't be penalized either. I think that would be considered bulldozing as well, AS LONG AS YOU'RE PLAYING THE BOT AND NOT THE BALL.

Re: Is Defense Finally Viable
 

You're assuming top goal defense is as easy as defense was last year. You need to design a mechanism that's going to extend 3'-4' out the top of your robot, linearly, not swinging around a pivot, that can withstand (presumably) multiple exercise balls hitting it at speed. Or you can spend you time designing a floor pickup, launcher, dump, etc. I think top goal defense is going to be too unimportant to top-rank offense/defense robots, and too challenging for most lower-ranked defense-only teams. I think I'd really rather that lower rank teams focus on a ball manipulation system than a defense system that's going to be useless 95% of the time.

Re: Is Defense Finally Viable
 

I think defense will actually be extremely effective this year. Keep in mind that there is going to only be one game piece for each alliance. This means that only one robot with a drive train that is fast and has decent acceleration will be able to follow their opponents' progress as they cross the field. They would be able to block robots from passing toward the goals, as well as blocking them from passing a ball over the truss and catching it. Also, a tall robot would also be able to park directly in front of a opponent that is attempting to score in either set of goals.(Just how one could defend against a full court shooter in Ultimate Ascent.)This defensive strategy could be effective with only one defender, which allows the rest of the alliance the ability to keep on scoring. Robots do not have to be in the goalie zone to block a shot. In fact, there is no area on the field that a robot can't be defended against.

Re: Is Defense Finally Viable
 

No protected zones => defense is viable

At its core this is a game of optimizing cycle time vs points scored by multiple assists.
With a good drive train and judicious use of those 6 CIMS it's going to be very worthwhile to add 15+ seconds to an opponent's cycle time and/or limit them to 2 assists.

Re: Is Defense Finally Viable
 

"Finally viable?" When was defense not viable? 2008 is basically the only time that happened. Even in 2012 there was still plenty of ball-oriented defense (and not to mention the triple balance defense nightmares).

But defense will be important this year.

Re: Is Defense Finally Viable
 

I would say, yes, only to a certain extent! What would be a game like to see all robots build for defense? While that could get you a little crack, the game will quickly become boring!

Re: Is Defense Finally Viable
 

Dear teams,

IMHO, while your limiting your opponents scoring by running defense, you are also limiting your alliance's scoring by not assisting. So there is no net gain to defense unless there are special circumstances such as a terrific autonomous mode where one alliance has a huge lead in points. and then just runs defense with two robots essentially shutting down the their opponents. This seems pretty petty and mean spirited, and not the gracious thing to do.

I hope people don't play this way. I think the most fun way to play this game is total offense. Figure out a way that your robot can maximize the scoring of your alliance no matter who your partners are. If you have two rookies on your side who can only pass balls, go for 31/40 points each cycle and try to get 4 cycles.

To rookies, build a RELIABLE base that can work every time and assist by passing the ball. Build your robot early and PRACTICE, PRACTICE, PRACTICE!
If you have trouble building your robot have your drivers practice with RC cars. Your first regional is not a good time to try to learn to drive.

If history repeats itself, I am guessing that defense will not be very important in qualifiers, but may be extremely important in finals. Because there are four alliance partners; one may well be a defense specialist that matches up well against an effective high scorer. Designing such a robot is risky, because it won't stand out in early rounds and have trouble getting picked. Being a defense specialist worked out well for Team 25 in 2000. They were so low in qualifying points that no one considered them for the third pick (This was a two on two game but the third robot was part of the alliance and you could play them at any time.) Since no one had scouted them their defensive strategy cleaned up and they were part of the National Championship alliance.

My final admission, I don't know how to build an effective defensive robot. Say I want to run defense against a highly effective high goal scorer like a fictional team called the 'Holy Doritos.' They have a machine that is maneuverable and fast can traverse the field in ten seconds and score, the turn very effectively and can automatically adjust their balls trajectory by use of an autonomous optical ranging system. So the can turn and shoot from any part of their scoring zone with 80% success.

How can I build a robot to defend against that? Even If I could it would at best slow them up and best case possible lower their efficiency 20 to 25%.
So they end up scoring 300 instead of 400, and meanwhile my alliance has scored 150.

Re: Is Defense Finally Viable
 

Defense was also pretty rough in 2011, once human players figured out how to throw tubes to their robots.

Re: Is Defense Finally Viable
 

Yup. Meaningful defense was near impossible once human players figured that out ;)

Re: Is Defense Finally Viable
 

I'm not one to advocate applying GP notation to [legal] match strategies, but the first sentence of this itself seems to miss a logical way to play zones this year. With a 3- (or 2-) pass zone layout for assisting, you will inherently have time in which you are not playing offense. One of the most logical options during that interim is to play defense. It doesn't--nor has it ever been--necessary to have defense as your sole occupation in order for it to be "viable".

Just a note, there are only 4 alliance partners at Worlds Elims, and even then you're only playing 3 at a time. Also, a note to rookies, the importance of defense in quals is highly (no, highly) dependent on your event/geographic region.

Re: Is Defense Finally Viable
 

Agree if each bot is working one zone then 2/3rds of the time you are doing nothing, so why not play defense ?

One simple strategy would be to get between the other 2 bots so they cant pass to each other.

Or get between the bot in your zone and the ball. They have to go around. If the ball rolls out of that zone they have to push it back into the zone or forgo the assist.

Re: Is Defense Finally Viable
 

I bet 987 could beat that :P

Have an ultrafast drivetrain with shifters. Build the bot to 5 ft as something blocking (lightweight so all the weight is at the bottom. Then have 2 rods that extend higher up to block the high shots! Make sure they are collapsible so you can get under the truss!

Re: Is Defense Finally Viable
 

Those rods would break or become illegal the first time someone shot at them. In order to score, I think our math came out at >20 fps to get to the high goal, so those balls are going to carry some force. That force has to go somewhere, so unless you build your rods out of unobtanium they'll either bend (and become illegal) or simply snap (in which case you'd be in violation of R9: Protrusions from the ROBOT and exposed surfaces on the ROBOT shall not pose hazards to the ARENA elements (including the GAME PIECES) or people.)

In short, it's very difficult to build a legal high goal defense system within a 6 inch cylinder.

Re: Is Defense Finally Viable
 

I'm having a long discussion with another mentor about this very subject. I'm the voice of offense, he is the voice of defense. He wants to sit in the goalie zone. My thought is (with the design I have in mind) that the extensions over 5 feet can be negated by robots who can get into position against the wall. Ramming/pushing strategy after said robot is in position can be negated by positioning with the alliance wall to the front and a side against one of the low goals.

I then came up with this evaluation for illustration's sake.

I went on to say that cycle times could vary plus-minus 20 seconds.

Defense has and always will have value. The question is how much value.

Re: Is Defense Finally Viable
 

I dont feel that defense is viable. Although three-robot assists, in my opinion, will be rare they are something that should have the opportunity to happen. Loosing a robot to defense will hinder the asist possibilities. I also feel that it will be extreme difficult to block the high goals. Ex. A single x-bar being lifted up will not be able to withstand constant hits (The balls are going to be shot with more power). A defensive robot will need a strong, reliable blocking mechanism that can expend upwards of 8 ft. The only defense that will be able to be played reliantly is the 1-point scores, which are not worthy enough to devote time to blocking. Defense wil not be viable in my opinion. :]


I agree with TheCascadeKid - these bars wil break or they will not be brought down and the refs will call the foul

Re: Is Defense Finally Viable
 

Stopping a pass (10 points) sure sounds like a defence to me.

With that said I would still focus on passing & scoring first and when possible defend.

Re: Is Defense Finally Viable
 

If you can keep a robot from scoring in the 1 point goal, you are also negating any bonus points that could be potentially scored. The ball must be scored in order to be awarded any bonus points.

Re: Is Defense Finally Viable
 

If you had a set of nested tubes ranging from just under 6 inches to 4 inches in diameter that telescoped up I think they could be rigid enough to remain within the 6 inch diameter limit even with deflection if the right material is used. Unobtanium would work, but aluminum or pvc would be more than sufficient.

Re: Is Defense Finally Viable
 

I don't think that making defense a top priority is a good strategy for this game. However, if you place the best defensive robot from your alliance in the zone with your goalie zone, after it makes a pass into the white zone, it could then defend the goals.

With this strategy, you can still accomplish 3 assists, as well as defend your goals for a large portion of the game.

Re: Is Defense Finally Viable
 

I'm surprised no one has brought up the idea of defense for the Auto period. There's been a little debate as to at which end of the field is considered an alliance's goalie zone on my team, but I don't see how it wouldn't be at the end in front of your opponent's goals. The rules say:
3.2.2.1 G4
When placed on the FIELD, each ROBOT must be:
A. in compliance with all ROBOT rules (i.e. have passed Inspection),
B. confined to its STARTING CONFIGURATION,
C. entirely within their GOALIE ZONE, or
entirely within the white ZONE and between the TRUSS and their GOALS, and
D. fully supported by the floor.

3.2.2.2 G5
For ROBOTS starting in their GOALIE ZONE the TEAM may decide if the BALL is: staged between the TRUSS and
the ZONE LINE and not contacting an ALLIANCE partner, or removed from the FIELD for the MATCH.

3.2.4.1 G15
During AUTO,
A. a ROBOT starting in the white ZONE may not cross fully beyond the TRUSS
B. a ROBOT starting in its GOALIE ZONE must remain in contact with the carpet in its GOALIE ZONE

So being, you should be able start lined up directly across from your opponents in the goalie zone, not put your ball on the field, then when the match starts extend your 6in cylinder and block your opponent's shot.

Re: Is Defense Finally Viable
 

I think that there needs to be some protocol as to which alliance sets up their robots first. If I saw a defending team setting up in front of my robot to block my auto shot, I would just move my robot such that the defense is no longer in the way. At this point in time I would expect the defensive robot to shadow me, which they have every right to do. However, this cycle of moving and shadowing has to end at some point, and there needs to be a way to decide who gets to make the final move.

Re: Is Defense Finally Viable
 

I think defense is viable. However, it should not be the main goal of a robot. It is pretty easier to design a sturdy net/wall/blocker and stick it on at competition. Obviously this takes some planning, but I think that an all-defense team is pretty limited. Our team is personally designing a robot that can catch and assist, with the ability to attach a defense mechanism if needs be.

Re: Is Defense Finally Viable
 

I would have to agree that 100% defense seems like a very limiting strategy in this year's game. Personally, I believe that a balanced approach seems like a good way to go this year. With the nature of the game, it is inevitable that each team will spend some period of time not actively involved in the offense, and in this time, some sort of defensive mechanism seems appropriate. however, playing entirely defense seems like a very risky strategy, as foregoing the ability to catch and shoot could prove very costly. Ultimately, I believe that balanced robots that can defend when they are not possessing the ball will have tremendous success this season.

Re: Is Defense Finally Viable
 

I'm not sure its legal. hitting the ball on purpose is for first offence a foul and after that a tech. I think bashing robots to stop successful passes and denying catches is the closest we get to D

Re: Is Defense Finally Viable
 

I think good teams will be able to quickly shift from playing offense to defense to interference with opposing defense and back.

I think being purely defensive is a losing strategy this year - there's too much missed opportunity for scoring assists (costs your team 20 points per cycle). And this is just my read, but I think being specifically a goalie specialist is a particularly weak strategy. It doesn't score any points, it doesn't prevent much scoring (if it prevents any), and it doesn't get in the way of any robots in the middle of the field. I think the goalie thing is a distraction.

If a team is trying to be realistic about their capabilities and is considering pure defense because it's easier to build for, I really hope they will consider instead finding a way to herd or carry the ball effectively and score in the low goal. And build a drive train with good traction (not mecanum or omni) and 4 CIM motors. If that's all you do, you'll give all of your alliances the potential to score a lot more assist points (helping with your tiebreakers) and you can harass the other alliance's robots all you want when you're not herding the ball. Edit: even if you can't score in the low goal, being able to push the ball where you want it to go effectively is really useful in this game.

Just look at the math: two robots touching the ball: maximum 10 assist points per cycle. Three robots touching the ball: up to 30 assist points per cycle. I think it's crazy to plan on never touching your alliance's ball.

Re: Is Defense Finally Viable
 

How about a mostly autonomous defense robot. Tracking a 2' red or blue ball may not be a very difficult thing to accomplish. You set up and keep the bot in the goalie zone, and it drives left and right to stay in front of the ball. If it is fast enough and responsive enough, it could keep the pole in front of the ball even while mid-air. With some clever extensions and a sliding post you could even guard the sections above the low goal, even though the zone doesn't extend that far.

Re: Is Defense Finally Viable
 

If robots can't hit an opponent's ball intentionally, what's the purpose of the GOALIE ZONE? According to the rules, a deflected ground pass is no different from a ball deflected in the air. According to the rules, if a ball is in a robot's way, it may bulldoze (single hit) it out of the way in order to get somewhere.

Re: Is Defense Finally Viable
 

All things considered you can't play defense if you focus on the ball. The rules on possession limit almost all intentional contact with the ball, the only exception is the goalie zone.
You can defend by pushing robots. As long as it's your bumpers pushing theirs you're fine. So i suggest you push them out of the way of passes, into other zones, and ultimately slow their cycle. You cannot erase assists, only delay the other team cashing them in.
That being said there is a 20 point leap for a third assist. Be a good offense bot when you can and slow the opponent when you cannot.

My interpretation of the rules is not official but i do believe it is against the rules and GP to intentionally control the other teams ball at all.

Re: Is Defense Finally Viable
 

To continue with what most people have been saying, a totally defensive bot is not a viable option this year but defense is going to be huge during all stages of the game. Of course getting the assist bonuses will be the first priority of all alliances this year but with only one ball in play there will be a lot of time where teams will be doing nothing to help their team and defense will be huge then. Blocking the one point goals and getting in the way of robots shooting for the ten point goals will cause more misses and the chance for less cycles, drastically changing the score of the game.

Also there might even come a time when we see counter defense against the robot preventing your alliance from scoring after the three assists and possible truss and catch. This strategy was implemented very well last year with the full court shooters and with no safe zones to shoot this year I can see counter defense becoming big in the later rounds of play.

Re: Is Defense Finally Viable
 

IF done right, a good goalie bot has the potential to severely impact its opponents. With the 20" extension rule, one could gain up to 40" of additional width/length. By using multiple vertical extensions that you deploy one at a time, what you potentially have is a 5' - 6' wide wall. Give it the ability to move and it just got bigger. If it can block one or more balls in Auto (favor the hot zone) the opponent has to scramble to score those before beginning a cycle. If they decide to not shoot in auto because they don't want to risk a block, you just cut out a potential 15-60 points. There is only one ball per cycle, and a bot that wide could cause a few delays in scoring.

I'm not saying it will or should be done, but it could be done, and it could be painful.

yes i know, it would be difficult to pull off and teams could always run counter defense, but anything is possible.

Re: Is Defense Finally Viable
 

Scoring in the top goal is not a simple task. And to add to the excitement we are already seeing reports of misshapen balls after moderate use.
But what really distinguishes Aerial Assist isn't the difficulty of scoring, it's the cost of a miss.
In 2013 a missed Frisbee meant a reasonable cycler got 3/4 of it's potential with no time lost.
This year a miss means at best wasted time hustling around the field trying to retrieve the rebound ball then resetting to score. If the ball bounces out of the field then there is a wait for the field reset volunteers to retrieve it and get it back to a human player - potentially at the wrong end of the field. Missing a shot really hurts an alliance.

Very few teams will build robots capable of scoring high goals reliably from a wide range of locations, and fewer still will be able to score while moving. So having a strong drivetrain and just getting in the way at the opponent's preferred shooting distance will be a viable strategy. Add some passive ball handling to push between zones and you have a capable robot.

Lasly, if we see a good specialist goalie robot this year with autonomous defensive capabilities then I'll be a very happy mentor.