Do defensive, low scoring tactics work?

[haverfordfords]

I apologize in advance if this was brought up before, but I haven't found anything on the topic.

Say you had a robot without an arm. Strategically, you could just take tetras from the human player and depositing them into the goal and repeating. Also, I guess you could play some sort of defense, possibly going as far as to remove tetras from the opponent’s goal. You could also get some tetras onto the field if requested. You would get back to the line for the bonus 10 pts. if applicable.

Now my question is, seeing as this strategy only nets a few points, would you call this 'bot valuable to the alliance? I sort of feel that in order to be liked by your alliance partners you have to get points and be offensive. Would you not pick a team with our strategy in the playoffs? Are we worth anything to other teams - do we have any value?

Basically, in the past have the successful teams been the ones with gung-ho offensive tactics that get many points, or can the little guys succeed as well, even though they may not contribute as many points in the end?

Do you need an arm to make a difference in the match? Do defensive, low scoring tactics work? What makes a "winning robot"? What are your thoughts?

[Stephen Kowski]

possibly going as far as to remove tetras from the opponent’s goal


you can't remove the tetras as you are describing from what I understand, but yes I believe defensive robots are a very valuable alliance partners....

[haverfordfords]

you can't remove the tetras as you are describing from what I understand, but yes I believe defensive robots are a very valuable alliance partners....

You can remove tetras from inside goals (as long as they are not stacked)

[dlavery]

Funny you should mention that. Check this thread (http://www.chiefdelphi.com/forums/showthread.php?p=327311#post327311) for some related discussion.

-dave

[haverfordfords]

Funny you should mention that. Check this thread (http://www.chiefdelphi.com/forums/showthread.php?p=327311#post327311) for some related discussion.

-dave

Thanks for that Dave!

[Holtzman]

YES!!!

Defensive tactics most definitely do work. Take a look at the last few years national champions. The scores may not be low, but defense played a HUGE roll in last few Championships.

2004 -All of the alliance's that made it to Einstein had great offensive robots in their alliance(469, 71, 67, 175). What set 71, 494, and 435 apart, was defense. 494 could play defense till the last 20 or so seconds then go hang.

2003- wildstang would get a lead in autonomous mode, then sit at the top of the ramp and defend their lead till the buzzer.

2002- well, there wasn't much anybody could do to stop Beaty

2001-wasn't a whole lot of point to defense here(four on none)

2000- well before my time. Maybe some of the guys that have been around for longer can fill in the gaps.

Defensive tactics work better in eliminations, when all your concerned with is winning. Qualifying rounds are a different story all together.

[Billfred]

I will argue the case for stacking, just to play devil's advocate.

Suppose Redabot can pick up tetras from the human player, then stack them. We'll say Redabot stacks three tetras. Worst case scenario, Redateam just scored nine points. If it's a row, we're talking nineteen.

Then consider Bluabot. It's a box on wheels. It also takes tetras from the human player, but it sends them underneath the goal. In order to match the scoring potential of Redabot, Bluabot will have to get those tetras under the goal three times as fast as Redabot can stack (as it would have to score nine tetras to Redabot's three to score nine points). If we assume Redabot is making rows, that speed for Bluabot balloons to roughly six times as fast in order to keep pace.

And Redabot's got the advantage of keeping at least those nine points, no matter what happens. So I'll ask the question--do you feel lucky?

[RogerR]

I will argue the case for stacking, just to play devil's advocate.

Suppose Redabot can pick up tetras from the human player, then stack them. We'll say Redabot stacks three tetras. Worst case scenario, Redateam just scored nine points. If it's a row, we're talking nineteen.

Then consider Bluabot. It's a box on wheels. It also takes tetras from the human player, but it sends them underneath the goal. In order to match the scoring potential of Redabot, Bluabot will have to get those tetras under the goal three times as fast as Redabot can stack (as it would have to score nine tetras to Redabot's three to score nine points). If we assume Redabot is making rows, that speed for Bluabot balloons to roughly six times as fast in order to keep pace.

And Redabot's got the advantage of keeping at least those nine points, no matter what happens. So I'll ask the question--do you feel lucky?
but how would the score look if Bluabot played defense and blocked Redabot from scoring any tetras instead of trying to keep up with Redabot. instead of being at a six point (at least!) deficit, blaubot and redabot would break even. blaubot could conceivably cancel out a much higher scoring opponent without ever touching a tetra.

[Billfred]

This is true--however, this field seems to offer plenty of Plans B. If Bluabot is blocking you, win a shoving match. Or whistle for a partner to come over and dance with Bluabot for a while. Or, retreat and head for the nearest wall--there's three more goals there.

Unless there is a wall involved (and there isn't too much wall this year, as the goals and loading zones take up quite a healthy piece of real estate), it'd take the majority of the Blue alliance to stop one offensive Redabot.

I'll be very interested to see if defense is as powerful as it has been in the past.

[Jeff Rodriguez]

but how would the score look if Bluabot played defense and blocked Redabot from scoring any tetras instead of trying to keep up with Redabot. instead of being at a six point (at least!) deficit, blaubot and redabot would break even. blaubot could conceivably cancel out a much higher scoring opponent without ever touching a tetra.

Bluabot won't be able to completely stop redabot from scoring. There are just way too many goals to try and defend.
The rules, also, lean toward offense, with the rules about the loading zones and de-scoring.

[russell]

Yeah, all redabot has to do is score once then bluabot has to take a break from defending and go and score four tetras to take the lead back, and while it does that redabot goes and scores four more itself, so bluabot has to go and score twelve more giving redabot time to score twelve more..... see a pattern? What happens if a match is tied.... like say tied at 0-0?

[Denman]

Basically, in the past have the successful teams been the ones with gung-ho offensive tactics that get many points, or can the little guys succeed as well, even though they may not contribute as many points in the end?

I disagree. Remember 2003, the Crates . The stealth hedgehog (our robot) could stack the boxes, but everytime it tried, the stack just got knocked over, by a "defensive" low point scoring robot....

I would like to think that one bluabot could hold up one or 2 of the redabots, giving the rest of redalliance a break to score more points. however, if there is a defensive robot on both teams, then they could just get into a shoving match .. .. ..

[nuggetsyl]

low scoring games work :yikes:

[MattB703]

Everybody keeps looking at this argument in an "all or nothing" fashion. I'm personally convinced that most of the elimination matches will involve one of the 3 robots playing "zone defense" on the other side of the field while the other 2 try to rack up points. The difference between winning and losing in many of these matches will be strategy of play.

[jrocket567]

Ever heard "The best offense is a good Defense."??
If one teams on an alliance is a box on wheels, and the other two can score points, that box can go be a PITA to the other team.. very effective.. just hope you dont get stuck with 2 or 3 boxes on wheels for a match..
j

[Swampdude]

I predict even if you're in a seeding match and all 3 teammates can cap. The one that's slower at it, or so so - will get relegated to this job regardless of their capping capability. It's an important aspect to cancel out the best capper of the opposing alliance with your weaker hand. Although if you had an alliance with 3 so so cappers against a 2 box bot and 1 good capper. I would attempt to out cap that 1 capper with all 3 of ours, and let the box bots take their shots. But I think the standard strategy will be at least 1 teammate playing that defensive "cancel out the opposing fast capper" role. On the other hand like it was said, you don't want to wind up with 2 or 3 of these on a team.

In the finals, these defensive chassis will get serious consideration during picks. But only if there drivers are effective. Simply bringing the chassis to the field doesn't qualify it. If you're going this route, you should be done with your build sooner and give your drivers as much time as possible to get good at blocking.

I think the winning team of regionals/nats will either consist of 3 good to great cappers. Or 2 good to great cappers and 1 really good defensive chassis. But the common denominator will be the best drivers and coach strategies. I don't see how a team consisting of 1 great capper and 2 defensive chassis can win at the top level. Reason, it's too easy to plow through a pile of bots and block that "great" capper. And if there's just one to focus on, with 2 chasing them down, it's just going to be a big pileup fest. I will say from experience though that blocking is very hard to do. Especially if your chasing a good driver/capper with a good chassis.

[Cory]

Ever heard "The best offense is a good Defense."??
j


Which is why the Baltimore Ravens are going to the Super-errrr nevermind... :rolleyes:

I do agree though. Defensive minded bots will be in high demand for the elims/

[cnield]

Defensive bots can generally drive around the opposite side and get in the way of robots that are trying to cap. If blue caps a goal on red's home row, and details a blue defensive bot to ferociously defend that goal, blue has denied red 10 pts (from their complete home row) and given their team the potential for two more lines and 20pts.

Defense will probably play a larger role in this competition than in any previous one. Since there are three robots per alliance, teams can afford to have a robot not scoring points for them.

One word of warning though, dont be too effective in defense in the seeding rounds, as you get your opposing alliance's points.

[Ianworld]

A defensive bot is really just a robot that can push harder and probably drive a tad better than another robot. So the result is that the strongest robot gets to do what it wants. Thats kind of a generalization. Even the strongest robot will get hampered by a weak robot playing defense assuming they don't completely outclass their opponent(4wd bot vs 2wd bot)

So that being said, every single team should try to have the strongest drivetrain it possibly can. If your stacking mechanism doesn't work you'll have a great backup plan. If it does work, then you'll be able to force your way through other robots.

That being said, i think defensive robots will play a key roll in this years game. Having a robot capable of stopping a cap that will alter the rows significantly will be a huge asset. Now that being said, this year you can't rely on defense. That won't cut it by itself. The team will be able to cap one tetra on a defensive robots watch this year. There are just too many options available. Each alliance will need to find the balance between capping and defense. It could be two defensive robots, one capper. Maybe two cappers and two defensive robots. The top alliance in Atlantawill probably include three fairly good cappers, of which one or two can play solid defense also. But at the regionals I'll take a bet that only two of the three alliance bots will be able to cap, thus forcing a designated defender.

[russell]

<G25> Strategies aimed solely at the destruction, damage, tipping over, or entanglement of ROBOTS are not
in the spirit of FIRST Robotics Competition and are not allowed.
While a box on wheels may not exactly be in violation of this rule I see this rule as being an attempt to discourage strictly defensive strategies, and I personally dont think they are in the spirit of the game. Whatever.

[Jeff Rodriguez]

While a box on wheels may not exactly be in violation of this rule I see this rule as being an attempt to discourage strictly defensive strategies, and I personally dont think they are in the spirit of the game. Whatever.

That rule has been in the rulebook as long as I can remember. I would say that it's there to keep a battle-bot from being entered.

Good defensive strategies have done very well in year's past. Watch last year's finals. 494 played outstanding defense.

http://www.soap108.com/2004/movies/cmp/index.cfm

[russell]

Im about 100 mb from going over my bandwidth limit so Im not watching any videos for another few days.... :D

[Madison]

While a box on wheels may not exactly be in violation of this rule I see this rule as being an attempt to discourage strictly defensive strategies, and I personally dont think they are in the spirit of the game. Whatever.

I see that rule as prohibiting you from installing a circular saw on the front of your robot and cutting through the chassis of your opponent. That's all.

[Joe Ross]

I'm going to add a little bit of more information and years to Holtzman's list.

2004 -All of the alliance's that made it to Einstein had great offensive robots in their alliance(469, 71, 67, 175). What set 71, 494, and 435 apart, was defense. 494 could play defense till the last 20 or so seconds then go hang.

2003- wildstang would get a lead in autonomous mode, then sit at the top of the ramp and defend their lead till the buzzer. 469 and 66 played defense the whole match as well.

2002- SPAM came very close to beating 71 by getting to the goal first. However, 71's strategy was fairly defensive as well, grab the goals and make sure no one else gets them. The offensive robots that year would have been the ball grabbers, like 173, 121, etc.

2001- wasn't a whole lot of point to defense here(four on none). However, there were many teams in the division finals that didn't ever score more points then the points for getting back to their end zone. I'd say those drive-train robots are similar to other robots of other years.

2000- 25 would move balls from the opponents goal to their goal with ease, and won the national championship.

1999- The finals were a battle of team 1 and 45 fighting over the puck and once one got on, keeping the other people off.

1998- 45 would remove the opponents balls off the ladders early on, and then load up the center. This was the last year before alliances, and a very balanced strategy won.

1997- 47 would shut down the center goal until the last seconds of the match. They made it to the finals doing this, and only got beat because Beatty was a little bit faster.

1996- From what I understand, 73 was a very offensive robot and won, but I don't know about the other teams around them.

[n0cturnalxb]

I've been reading this thread for the past few days (.. okay, so I skimmed the last few posts!), but..

Even though defense MAY be a good strategy, I don't necessarily think it's wise to build solely for defense. My team was leaning towards the defense-only strategy and I.. became very annoyed, very fed up.

What's the point of building a box on wheels?

That's all I really have to say. Build for offense, but make your robot sturdy. Make your chassis strong. That way, you have two options and you're not so limited - if your alliance doesn't have enough offense, you can contribute; but if you have too much offense and not enough defense, your robot can STILL DO defense. ... Whereas, if you built a box on wheels.. you're not going to be able to contribute much to offense, whether you want to or not.

[Alex Salomonsky]

I've been reading this thread for the past few days (.. okay, so I skimmed the last few posts!), but..

Even though defense MAY be a good strategy, I don't necessarily think it's wise to build solely for defense. My team was leaning towards the defense-only strategy and I.. became very annoyed, very fed up.

What's the point of building a box on wheels?

That's all I really have to say. Build for offense, but make your robot sturdy. Make your chassis strong. That way, you have two options and you're not so limited - if your alliance doesn't have enough offense, you can contribute; but if you have too much offense and not enough defense, your robot can STILL DO defense. ... Whereas, if you built a box on wheels.. you're not going to be able to contribute much to offense, whether you want to or not.

I agree, people on my team want to build soley on defense too, and I think its stupid, defense ,IMO, is a last resort when you go to comp. and you find out your lifting device is ineffective. Plus, you're relying on the fact that your partners are not soley defenders as well, like football, you can't with all defense and no offense. Plan for offense, if ineffective, play defense.

[russell]

Exactly. Anyone can play defense, but only offensive bots can play offense. Keep your options open. Hey a tetra manipulator should make a good defensive "tool" anyway.

[Corey Balint]

Well, in my personal experience, low scoring defensive robots can work very well. In team 25's history we have focused alot on defense. In 2000 we had a bot that reached into the other teams goal and stole the balls away and in 2003 our sole purpose was to push robots out of the way. Last year we had changed our theory to offense, and it came out poorly during the season. However, we did manage to get to two quarterfinals in regionals. In our first offseason, we had a major problem with our arm and could only drive around. So we decided just to play some good defense. We end up winning 5 qualification rounds just playing defense, and then going to a thrilling 3 match quarterfinal vs 222 and losing by just one ball(ironically having no offense came back to hurt us :rolleyes: ). So we decided to keep this strategy for the rest of our offseasons. We ended up winning 3 and placing 2nd in the other, playing pure defense.

We did have help from offensive robots though. So it really depends on the game, and on the balance of what is now a 3 robot alliance. In the past games you could get away with one main offensive robot and one defensive, now, I think you will have to blend the robots better. A pure defense with no manipulator, may not be very practical, because some teams will be able to break through the defense easily. It is basically vital to have something to move the tetras around this year, no matter where you place them.

[Andrew]

Once more...the offense versus defense argument.

A team which designs specifically for defense will be very effective in this competition. A box on wheels which can't do anything else is not a good defensive robot.

That having been said, the purely defensive robot, this year, is not going to do as well in competition as it would in years past. Why? It is possible to play defense against two robots simultaneously, freeing your alliance partner to score. However, three robots at once will take its toll on the purely defensive robot.

Match after match, making contact and disrupting, will leave most purely defensive robots severely compromised come eliminations.

The other two issues this year that make pure defense a difficult proposition...the kit drive train and the 30 point loading zone penalty.

Even a six motor drive system bot will not be able to effectively fend off TWO kit bots much less three.

If the driver of a defensive robot gets hung up near an opponent's loading zone, the thirty point penalty will negate the most effective scoring strategy.

[Rick TYler]

Who cares if boxes-on-wheels do well in the tournament? They're boring to build, boring to run, and boring to even look at. Winning isn't the only goal here. I'd rather see the students in our team field something with eight really cool features that they can be proud of than a first-generation Battlebot that goes to regionals.

[CRAZYMADI]

This year game is not only complex as far as technology goes, but also about the strategies teams have to use winning the game.
This year game heavly depends on the kind of strategies each team will use. even with the heavy technology, eaach team have only one option ;;;;; to be defensive or offensive. In either of the cases......... the ccommunication among th teams will dominate the whole 2 mintue session. The scouts, captians, coach and the drivers have to use their 6th sense in figuring out a way in and out of the field, with as many points as they can score.

Madi
----------------
"Think in terms of what you can think by not thinking what you can't think, but you can also think about the fact that you are thinking about something which somebody has already thought off."

[russell]

I donno, I was thinking that building this year would be easy, but today we realised just how much torque is needed to move one of those tetras.

[Mike Ciance]

A defensive bot is really just a robot that can push harder and probably drive a tad better than another robot. So the result is that the strongest robot gets to do what it wants. Thats kind of a generalization. Even the strongest robot will get hampered by a weak robot playing defense assuming they don't completely outclass their opponent(4wd bot vs 2wd bot)

So that being said, every single team should try to have the strongest drivetrain it possibly can. If your stacking mechanism doesn't work you'll have a great backup plan. If it does work, then you'll be able to force your way through other robots.

That being said, i think defensive robots will play a key roll in this years game. Having a robot capable of stopping a cap that will alter the rows significantly will be a huge asset. Now that being said, this year you can't rely on defense. That won't cut it by itself. The team will be able to cap one tetra on a defensive robots watch this year. There are just too many options available. Each alliance will need to find the balance between capping and defense. It could be two defensive robots, one capper. Maybe two cappers and two defensive robots. The top alliance in Atlantawill probably include three fairly good cappers, of which one or two can play solid defense also. But at the regionals I'll take a bet that only two of the three alliance bots will be able to cap, thus forcing a designated defender.makes me glad that my team is always critisized for an "overly-powerful" drivetrain :p

[Denman]

yes, we had an overly powerful drive train last year.... This year we are going to be adding bumpers a much better drive code to stop it lol.

I think the game will probably run really defensive - everyone blocking each other, or really offensively - mad stack . I dont think it will be possible to have something in between...

[jesus]

yup defense does help we saw a lot of people get whooped by the grease monkeys :ahh: :eek: i saw them ram into Robonauts and knock off their arm

[Eria4044]

yup defense does help we saw a lot of people get whooped by the grease monkeys :ahh: :eek: i saw them ram into Robonauts and knock off their arm

Note to self: don't build an offensive robot that falls apart upon impact. That would be quite a site. :yikes:

[EricH]

NEVER underestimate defense bots. Last year, we won almost all of our nationals rounds (except the first, which 71 won for us) in qual matches by playing really good defense on the bar. One of the reasons our alliance lost the semifinals was because another robot knocked us off the platform before we got into defense position.

--Eric

[AJunx]

I think FIRST did an excellent job this year of making a game where simple-minded box-bot strategies are effectively worthless. There are, however, certainly defensive strategies that could be very effective. Fortunately, those strategies will require a bit more thinking than just "getting in the way." Such strategies might include closing off parts of the field, using part of one's robot to cover the top of a goal (or more than one), etc.

Defensive strategies this year will require robots like the one Team 25 built in 2000 (which to this day is the most impressive, well-designed robot that I have seen).

The reasons I think box-bots will be ineffective this year:

-6 robots, 9 goals, you do the math.
In recent years, the number of "goals" has always been limited (1999, 2000, 2002) and/or centralized and immobile (2000, 2003, 2004). To see that these set ups were prime for defense one need only look to military history: successful defenders defended the smallest, highest area possible. The field this year presents no true center. And a robot doesn't really have to travel very far in any direction to be find a goal.

-Take a look at the field:
http://www2.usfirst.org/2005comp/Section_3-The_Arena.pdf
As soon as a robot is done getting a tetra from the loading station they can 1) get another tetra, 2) turn to the right and go to a nearby goal, 3) turn to the left and go to a nearby goal, 4) go backward for a few feet and have 6 goals immediately nearby. The only one of these four options that a box-bot could legitimately "defend" would be #4, as it cannot hit a robot in a loading station, it cannot pin the robot up against the wall for (10 seconds?) and it cannot touch a tetra being held by another robot. Looks to me like the box-bot hasn't got a chance.

Cheers to offensive and defensive solutions,
Andrew