Best defensive strategies
 

After reading a thread on some possible defensive strategies, I started thinking about more effective defensive strategies used in the past. What are some of the best defensive strategies robots have seen in the past? Pics or videos would be awesome!

Re: Best defensive strategies
 

One of the best defensive robots that I've seen was team 3553 last year. They had a great system that unfolds to double their length, and were therefore extremely successful in blocking others. Their CAD file can be seen here.

Re: Best defensive strategies
 

The bar blockers in 2004.

This class of robots, half a dozen in number, could pull a 200-point swing in a match. At 50 points per robot on the bar, the blocker would go up (50 points) and block one or both of their opponents (50 points each) and then allow their partner up (50 points) for a possible 200-point swing. The real fun came when two bar blockers went at it. I seem to recall one of them pinning another on the bar...

It gets better, though. Two of the bar blockers could eliminate a doubler ball from the bar. Opponents could place the doubler on a goal, but these two robots could remove the doubler.

Robots to look up: 64, 190 (stationary with capacity to steal the doubler ball), 237 (there is video of 190 vaulting over them), 330 (the other with un-doubling capability), 868 (the only one to make Einstein), 1266 (a rookie that year).

Re: Best defensive strategies
 

Playing Defense is the act of preventing the other team from scoring.

As such it can be used before, during, and even after the scoring process of the opponent.

Before: Tube starving this year. Taking a tube the other team was trying to pick up. Pushing tubes into the lane so the opponents can't get to them. ect.

During: Activly attempting to stop them from actually scoring points. T-boning, zone defense, ramming ect all fall under this. This is probably what most people think of as defense.

After: generally descoring, or the act of taking their points away. FIRST has been trying to get rid of this type of defense in recent games. Often times it is illegal to descore. However, it is arguably the most effective method of defense because it (usually) involves the most reward for the least work. Example: this year knocking off a logo piece on the top row at the end of the game would have been more effective then playing robot on robot defense the entire match. (of course that's why it was illegal.)

Re: Best defensive strategies
 

Where would one be able to find this video? It sounds awesome!

Re: Best defensive strategies
 

Ditto! I would love to watch a match like that!

Re: Best defensive strategies
 

My soccer coach always told me "The best defense is a good offense".

On that note, I'd like to say that 71's '02 bot was a great defensive robot, just because it could dominate the offensive side of the game.

As for strategies, offensive-defensive strategies could include scoring as many game pieces possible to ensure that the other alliance does not get any. This relates an iteration of the tube starvation this year, and a possible strategy in '09 (wasn't there back then, but it is probably a viable strategy).

Re: Best defensive strategies
 

One of the most epic things I have ever seen in an frc match
http://www.youtube.com/watch?v=Q5nnGGRi-94

Re: Best defensive strategies
 

Wow, thanks, that's incredible! :ahh: :yikes: :ahh:

Re: Best defensive strategies
 

This is a debatable statement. Not all defense is stopping the opponent from scoring. Defense can be stopping the opposing alliance from scoring, but it also can be getting in the way and making it harder for them to score. If you can't block the opposing robot from scoring, at least make it earn the points that it is about to attempt. Ive seen even the best drive teams stumble when their strategy of easy scoring didn't work. This topic was brought up in the thread where it talked about mecanum wheels and defense. http://www.chiefdelphi.com/forums/showthread.php?t=91401&page=4&highlight=mecanum+wh eels+defense

Re: Best defensive strategies
 

The best offensive robot in the world is going to have a hard time scoring if they can't acquire game pieces...

Re: Best defensive strategies
 

One offseason robot vault coming right up! http://www.youtube.com/watch?v=Q5nnGGRi-94&NR=1

237's slider mechanism is inside the black "mailbox". Oh! Forgot to mention: 190 was the only stationary robot in the 2004 bar blockers. The others all had a sliding mechanism.

Re: Best defensive strategies
 

237 was brutal that year! Such a sick robot for the 04 game.

Re: Best defensive strategies
 

Sorry Eric, but O'Sancheski beat you to it! Thanks anyways though! That was some amazing footage!

Re: Best defensive strategies
 

Well, along the same lines as "the best defense is a good offense" 469's 2010 Breakaway robot comes to mind. We, as 2410, had the honor of assisting them in a Curie match and boy was the score in that match for us high. Their starvation cycle really caused a lot of elite teams fall prey to their strategy. It's amazing they did not win World Champions, but lost to 3 even more amazing teams off of points alone.

Re: Best defensive strategies
 

Is that really a defensive robot, or an extraordinarily good offensive bot? I guess it can be considered both? ::rtm::

Re: Best defensive strategies
 

The best defense is a good offense, and the best offense is a good defense.

I think these two phrases represent 469 in 2010. I just love that design! Plus, if assisted correctly from alliances, it's possible to have all of the balls in your front zone, creating the perfect starvation tactic! I LOVE IT! :D

Re: Best defensive strategies
 

By that definition, it does technically prevent the other team from scoring, due to the scorable items, or lack thereof created. So, in a sense, yes, it is defensive. Though I agree with Hallry and SuperNerd256: 469's bot was just extraordinarily amazing.

Re: Best defensive strategies
 

Getting in the way and making it harder to score IS stopping the opponent from scoring. By doing this they score less then they otherwise would. This type of defense would fall under the "During" which I have requoted and bolded for your convinence below.

When considering defense one must look at the "net value" of the defense. Basically, this amounts to if your robot can more positively impact the score by stopping the opponent from scoring rather then by scoring themselves.

Ex: Red scored 20 and Blue scored 17 with all robots attemping to score. In the next match Blue places its weakest robot which only contributed 2 points in the previous match on Red's strongest scorer which scored 10 of the points in the previous match. In this match all of the other robots contributed similarly except the weakest Blue robot which scored no points (-2 because it did not score the two points it normally does) However, the strong Red robot was only able to score 4 points as a result of Blue's defense (+6 for the Blue alliance because Red scored 6 points less then it otherwise would have been able to.) This resulted in a match 20-6=14 to 17-2=15 Now the Blue team wins as a result of smart defense.

I hope this kind of shows how defense can be a smart play. A very important note with defense is that when your alliance is deciding how to play you must make sure you maintain your offensive power. Basically in order to make defense effective, your alliance still must put up points. On the same note, if the defense being played is ineffective, then you are putting your self in a loosing situation.

Ex: Using the same example above, if the weaker Blue robot can only hold the strong Red robot to scoring 8 points instead of ten (+2 for Blue's defense and -2 for lack of offense) there is a net gain of 0 points and the defense was unwarrented. Using a different deffensive method, the weak blue robot now pushes all tubes on the opponents side of the field into the lanes. This affects all three of the opponent's robots negitively. Lets say strong Red was fast and still able to put up 8/10 points. However, the other two Red robots were less able to cope and put up only a combined 6/10. This results in Blue's -2 for lack of offense. However, Red scored only 8+6=12 out of 20. 6 less then they normally would (+6 for Blue). Now the score is 20-6=14 to 17-2=15 again a win for Blue using smart Defense.

In conclusion, Defense (and Offense) are all about maximizing your "net score." Because of this, finding effective ways to defend using minimal effort while still recieving results is key to success in any FRC match.

This is a really interesting topic, defense is definatly more then just hitting people.
Regards, Bryan

Edit: 469's 2010 robot played "Before" defense. preventing the opponents from being able to aquire game objects in order to score them. However, they were able to do this while also scoring at the same time. Because of this their "net score" was doubly effected. Not only were they scoring 10+ a game but they were recycling 3+ balls that the other team couldn't score with and usually drawing a defender to play "ping pong" which was a another loss of points for the opposing alliance.

Re: Best defensive strategies
 

That slider was TOUGH to get around. Here's one of my favorite pictures from 2004. It's our robot (team 11) hanging on the claw mechanism of 237. It didn't count as a hang because werent being fully supported by the bar, but the battle to even get in that position was epic.

-Brando

Re: Best defensive strategies
 

That looks like it was before they added the mailbox. Made it a little easier to hang on them when they didn't have it on.

Oh, and it was only tough to get around them if you were slow getting onto the bar (AKA, not a bar blocker). 330 forced them to play defense on the ground in Archimedes on at least one occasion.