Defensive robots

[sagi34]

Originally Posted by Boltman

With limited time in the game I do not see how a defensive bot shifts the odds in their alliance's favor overall. There are 16-18 scoring plays that either involve crossing a defense twice or cycling a SINGLE ball. All in 135 seconds. For either ranking or huge elimination points.

With only two bots that puts cycle times in into the danger zone to do 16-18 plays with 16 single actions that take 8.43 seconds average for one bot to complete 16.43 seconds for two bots 25.31 seconds for three bots working together.

16.43 average cycle is asking a lot of two bots to either cross a defense twice -or obtain a single boulder (perhaps from opponents castle location to your secret passage) and successfully deliver a boulder accurately to weaken the opponents castle again. OF course if every bot every time crossed and shot it would be more doable but still very difficult to ensure it happens every time with one bot let alone all three bots.

Also consider last 20 seconds is endgame time not a lot of scoring going on as teams are scrambling to get on batter and climb.

Its the same as 2014 just different, more to do and no obvious multiplier action, more single actions that all take time and I think a well coordinated team of 3 beats 2 and a defender...we'll see.

A defensive robot can steal 1 ball and score it to the low goal when coming in the last 20 secs, so it leaves the 2 other robots to score 7 balls, a defnsive robot can cross 1 defense in auto and then when he comes in the last 20 seconds he can cross it again and destroy it, that leaves the other 2 robots to cross twice 3 more defenses, lets say that each can cross 1 time in auto and only 1 robot can score the ball in auto. now you have 2 robots that need to cross defenses 4 times and score 6 balls, lets give them 15 seconds to capture, that leaves them with 2 mins to do 10 tasks, 5 tasks per robot, 24 secs for each task, not so hard when no one plays defence on you and you have enough place to manipulate.

[Louisiana Jones]

Originally Posted by Boltman

With limited time in the game I do not see how a defensive bot shifts the odds in their alliance's favor overall. There are 16-18 scoring plays that either involve crossing a defense twice or cycling a SINGLE ball. All in 135 seconds. For either ranking or huge elimination points.

With only two bots that puts cycle times in into the danger zone to do 16-18 plays with 16 single actions that take 8.43 seconds average for one bot to complete 16.43 seconds for two bots 25.31 seconds for three bots working together.

16.43 average cycle is asking a lot of two bots to either cross a defense twice -or obtain a single boulder (perhaps from opponents castle location to your secret passage) and successfully deliver a boulder accurately to weaken the opponents castle again. OF course if every bot every time crossed and shot it would be more doable but still very difficult to ensure it happens every time with one bot let alone all three bots.

Also consider last 20 seconds is endgame time not a lot of scoring going on as teams are scrambling to get on batter and climb.

Its the same as 2014 just different, more to do and no obvious multiplier action, more single actions that all take time and I think a well coordinated team of 3 beats 2 and a defender...we'll see.

I predict that the winning alliances of 80% of the regionals will have a robot playing defense in the courtyard for at least 1 minute of matches they win. The only exceptions will be teams that somehow get three efficient scorers that can all shoot quickly from safe zone, and know they can outscore the other team. It's to easy for a robot that can't score efficiently to switch to defense and then disrupt the other team by bumping them as they shoot. Most teams shooting high goal will take a second or more to line up, which will make them very susceptible to being defended. Robots that aren't shooting from the safe zone will take a beating as they attempt to line up and shoot. Shooting high goal from the batter is worse, as a defender can simply bump your backend sideways as you line up to shoot and then slow you in retrieving your missed shots, maybe possibly depositing the boulders in the secret passage to prevent you from ever retrieving the boulders. Has there been any clarification on whether a defender can park behind a robot that has driven into the batter? A defender could effectively delay that robot indefinitely if legal. Not a bad tradeoff if the robot you block in is the other teams high scorer.

[Dezion]

Originally Posted by Louisiana Jones

. Has there been any clarification on whether a defender can park behind a robot that has driven into the batter? A defender could effectively delay that robot indefinitely if legal. Not a bad tradeoff if the robot you block in is the other teams high scorer.

Refer to Q733 for clarification.

[Green Potato]

I WOULD argue that a defensive bot is a positive inclusion for an alliance, IF the game was all about getting the win. If this game were 2014 or 2013 style of qualification point acquisition, I'd take a defensive robot in a heartbeat.

The problem is that this game isn't 0-sum. In fact, some matches could be concievably played where the LOOSER makes just as many qualification points than some other match't WINNER.

That's important.

That means that there is a direct, positive incentive for a robot to play offense, although sometimes ineffectively, over defense. Sure, 2 robots on paper might be able to breach by themselves, and only need robot 3 to capture the tower, and, yes, I anticipate that such may certainly be the scenario at eliminations or championships. But, the fact of the matter is, things go wrong. You get stuck due to a bad angle and terrible visibility. Your robot just won't move. The opposing alliance sent a robot just to guard you. Sum it all up, and there's a good chance that at least 1 of the 2 offensive robots you planned on breaching with can't function fully. Should that happen, I'd much rather be able to have that robot that can at least get me that one qual. point for breaching over a defensive bot that only propels us to a 0-QP match.

Even in elims, the amount of points for a breach is s pretty darn big number, and given the high goal is so small, a robot with a strong drive train that can help breach (and maybe have a pool noodle) may be almost all you need.

[Type]

Originally Posted by Dezion

Considering that most high shooters also seem to be going underneath the low bar, it will be easy to block shots with the right design. I can't state how many robots will be designed for this, but those that are designed like this will probably go into eliminations. After a team has two good high shooters and breach bots, a defensive robot would be a great option for the last member of their alliance.

Defensive drivers will have to be cautious though as to not incur penalties (of course, all drivers should be cautious regardless of their posistion on the field.) Pinning an opposing robot and pinning too soon may be very common penalties for a defensive bot. As well, defensive drivers must ensure they are out of the courtyard in the last 20 seconds, which I would not believe to be too much of an issue, as they would more than likely have a scaling device, due to the fact they would not be under the constraints of the low bar (meaning, depending on their design, they would have to raise their robot less or it will br easier).

A strong breach bot may fall back to defense after most of the opposing alliance's defenses have been damaged. This would occur more often if the breach bot could not score a high goal. I know that this will probably be our teams strategy if we are not needed to continue scoring goals or crossing defenses.

For example, an alliance may have a robot that can do the Low Bar, Cat B, and Cat D; a robot that can do Low Bar, Cat B, and Cheval; and a third robot that can do all defenses (or the vast majority to qualify as a breach bot). The breach bot would damage all the defensss the other two could not do, then play defense. As the other two robots went and scored goals, they would go over the defenses that they can, breaching all defenses, and scoring.

Strategies that utilize each robots' strengths and makes up for their weakness through collaboration will be the ones that succeed and win.

I don't really want to talk that much about my teams strategy since we haven't finalized it but we were thinking for our robot we could cross all of the defenses (including low bar), then also shuttle balls back and forth in the process so a taller, more accurate shooter could shoot quicker and not have to traverse the defenses to get another ball. We designed our robot to shoot high goal but it may not be as effective as a taller shooter.

[Dezion]

Originally Posted by Type

I don't really want to talk that much about my teams strategy since we haven't finalized it but we were thinking for our robot we could cross all of the defenses (including low bar), then also shuttle balls back and forth in the process so a taller, more accurate shooter could shoot quicker and not have to traverse the defenses to get another ball. We designed our robot to shoot high goal but it may not be as effective as a taller shooter.

I agree with our strategy and it may be something that we do. As we breach defenses, we'll possibly carry a boulder over; and if the situation is safe (the opposing alliance can't steal our boulder), we can drop it for an accurate high shooter. We could also just go from the secret passage, through the low bar, and drop for a teamate. This would help decrease cycle times for high shooters and utilize more points. Of course, our robot could also do defense. Defense is a necessity, but strategies may exist without them. How functional they will be I'm unsure of, but with proper execution, any strategy can be a threat.

[Lil' Lavery]

Originally Posted by Dezion

Refer to Q733 for clarification.

Care to provide a quote? Q733 is not included in the last Q&A PDF.

[BoilerMentor]

Originally Posted by waialua359

Yes, with a pool noodle, it will easily do the job.
That high goal opening is just way too small to have any kind of deflection not be effective.

My point that is that the energy the boulder is carrying is related to the effectiveness of a blocker. We had a pretty significant interference in practice the other day and still hit a shot. A small action camera, heavier than a GoPro went flying across the room after being ripped off a mount and the ball still hit its target.

We attached PVC and strung across a t-shirt in 2013 and it worked pretty well as a deterrent, but that shooting position was pretty concrete. A team capable of shooting from the defenses from any position 1-5 can gain an advantage in that way. Also, if you can shoot quickly, it makes it harder. A robot that pops across and rips a ball off at the goal presents a scary defensive situation, because you have to basically guess at being out of range for penalties.

1747 has a pretty strong defensive legacy. As someone who spent a huge amount of time coaching what a number of people have observed as very clean, effective defense I can honestly say defending a shooting robot crossing the defense presents one of the largest defensive penalty risks we've ever seen.

But that's just my 2 cents.

[waialua359]

Originally Posted by BoilerMentor

My point that is that the energy the boulder is carrying is related to the effectiveness of a blocker. We had a pretty significant interference in practice the other day and still hit a shot. A small action camera, heavier than a GoPro went flying across the room after being ripped off a mount and the ball still hit its target.

We attached PVC and strung across a t-shirt in 2013 and it worked pretty well as a deterrent, but that shooting position was pretty concrete. A team capable of shooting from the defenses from any position 1-5 can gain an advantage in that way. Also, if you can shoot quickly, it makes it harder. A robot that pops across and rips a ball off at the goal presents a scary defensive situation, because you have to basically guess at being out of range for penalties.

1747 has a pretty strong defensive legacy.

But that's just my 2 cents.

A good question here now is what happens when the opposing alliance puts a team out of the 15" max extension. I dont think the answer is clear cut and dry unless I missed a rule. In the past, that was a subjective call.
Also, I know all about the defensive history. That's why I chose you in 2013.

[Rockant]

I think that defensive robots might be a good third robot on an alliance, but that overall, the amount of good shooter robots will be very limited at most regionals. What this means is that a defensive robot may be a better last pick, just because every team's priority could theoretically be to get a good shooter on their alliance, just because of the points potential. I could be totally wrong here. I think we'll just have to wait and see.

[BoilerMentor]

This whole line of questioning is leading more towards a Q&A involving robots on top of other robots, which may be a startlingly common occurrence with all the short robots and the ready-made ramp that is the CDF. That is assuming someone decides to take the interference penalty(s) in trade for preventing a breach, which at some levels of play might be a possibility.

*edit* Also, Glenn, I know you know the defensive history. That sentence was for everyone else's benefit. *edit*

[pilum40]

haha...that's why our robot will have a "steel top" (thin) and a steel glacis plate (thicker but not too thick for weight limits with rhino drive) ala my old trusty M1A2. This game promises to be more rough and tumble this year. I'm cool with it. The team is looking forward to it as well. We're stoked for the competition to begin!

[waialua359]

Originally Posted by BoilerMentor

This whole line of questioning is leading more towards a Q&A involving robots on top of other robots, which may be a startlingly common occurrence with all the short robots and the ready-made ramp that is the CDF. That is assuming someone decides to take the interference penalty(s) in trade for preventing a breach, which at some levels of play might be a possibility.

"The #1 factor in causing robots to end up on other robots is........"
I thought about this for awhile because of what happened in 2010. The key is bumper placement, and it is a critical factor especially with defense. We made sure our bumpers were..

[Dezion]

Originally Posted by Lil' Lavery

Care to provide a quote? Q733 is not included in the last Q&A PDF.

Sure.

Originally Posted by Question

What constitutes as a pin in this year's game? Does the defensive robot have to initiate contact? If an offensive robot is on the tower battens trying to score in the tower and a defensive robot parks behind them without initiating contact and the offensive robot cannot get off the batten is this considered a pin?

Originally Posted by Answer

There's no FIRST Robotics Competition specific definition of "pinning." From Merriam-Webster's Dictionary: a pin can generally be defined as "to prevent or stop (someone or something) from moving." There is no requirement of contact for pinning to occur. While we cannot rule absolutely on hypothetical game scenarios, generally speaking, parking behind an opponent ROBOT that is on the BATTER would be considered pinning as the dividers on the BATTER, combined with the pinning ROBOT, would prevent the opponent from escaping.

So, parking behind an opposing robot on the batter is not aganst the rules, but you must follow all rules related to pinning.

[FrankJ]

Originally Posted by waialua359

A good question here now is what happens when the opposing alliance puts a team out of the 15" max extension. I dont think the answer is clear cut and dry unless I missed a rule. In the past, that was a subjective call.
Also, I know all about the defensive history. That's why I chose you in 2013.

G43 is pretty clear. If your bumpers are in the outerworks, you are considered to be transversing. You can use an appendage to force a blocking robot back. You cannot use an appendage to get yourself closer to goal while being protected by being in the outer works. Although the defensive robot being that close to a robot in the outer works is risky business.