The FIRST day...

[Clanat]

We also drove our robot off of the top of our ramp this year. It was a lot of fun

[David.Cook]

Originally posted by etoleb
After watching pieces of the VCU regional, I was very suprised to see virtually no stacking attempts, with the exception of bots picking bins up and holding them (were there mechanical problems or something?). Am I totally missing something? Maybe the "stacking is useless" rumor has been convincing teams to not even try? Perhaps drivers don't have enough practice and their stacking mechanism needs fine tuning? Does it just take too much time for some teams? Could it be that its so confusing in the alliance station that drivers are distracted?

OK, I'll give you my thoughts. I thought stacking would be more useful. But I was at VCU, and my belief now is that it isn't.

Reasons:
1) Bots are way too fast, and it doesn't take much to knock down a stack.
2) Yes, stacking takes tooooooooo looooooooonnnnngggg! Several attempts were made at VCU - all of them failed.
3) It is easier and more statistically likely that you can defend a stack if you have a good sturdy pusher in your alliance. This was demonstrated in several matches at VCU.

Some anecdotes:
There were two teams with GREAT multi-stacker bots, Robodogs and team 122. Both have excellent designs, but in the end were unable to set the stacks down successfully. Robodogs almost got theirs down, and I think it would have won the match, but the bottom bin was crooked and the stack was still touching the bot when time expired. 122 never placed their 4-stack without it tipping over - either due to external bot bumping or their own wobbling - I really don't know which.
Team 388 (congrats on the Chairman's award!!) was able to pick up and manuever a single box, and was in a match where I think they could have won if they had gotten it stacked, but fast little bots running around and bumping them foiled the attempt.

I am sure somewhere there exists a bot that will successfully stack to win - I actually hope for it. But it will be the statistical outlier, not the bell curve.

[sevisehda]

The thing I noticed was that the crates didn't seem to be the way I expected them. The boxes seemed to be in every orientation in closely packed groups. To complicate things further these groups would move at the slightest bump. I saw many bots trying to get a box out of the mass just to get a hold of it.

I surprised we haven't seen any stack kidnapping yet. I thought some of the stack-huggers would grab a human player stack, shove for a minut then place it near the end.

Hopefully the teams competeing next weekend will start to rethink the ideas to solve the problems experienced today/yesterday.

[Willum]

If you watched the ohio regional on webcast you would have seen that RIT built up a stack of 4 very quickly. And it lasted bc most teams were fighting for the ramp by then. The would eventually lose the match and be eliminated, but it stood as the only team to effectively stack intentionally.

[Yan Wang]

The matches have been quite disappointing. A robot like ours could easily stack/orient 3 bins in about 20-30 seconds depending on the mess. With those few bins in a stack, you can easily win a match and it's not tall enough to be knocked down (well, depends on your design)... I still don't understand WHY stacking robots didn't try to stack. The lack of attempts just puzzles me.

[David.Cook]

Let me debunk that theory...

A stack of two can be easily undone. What is happening is bots are just running into the base bin full speed from a few feet away and they go flying. Also, the side walls help cause motion when bins are rammed against them.

One example from VCU, with 15 seconds left to go, our bot was hung up on the side rail. We got loose, rammed the stack to break it, wheeled around from the corner of the field and made it onto the ramp to hear "2, 1, times up!"
(I don't mean this boastfully... we were all sweating bullets at the time. I don't believe our driver pulled it off.)

I do agree with you, that if you can stack three or four in 20-30 seconds you can swing a match. Provided there are enough bins left in the scoring area. It seems a fair number are getting knocked out of the playing area.

CORRECTION: My son reminded me that the Robodogs were able to pick up a human player stack of four and placed it on another bin to make five, then they repeated that to make a six-high stack. This was during a qualifying round.

[Mullen]

alot of people are saying stacking is a waste of time. it is and it isnt, it all depends on your stacker. if you get a stacker that hold it internally, much like team 73, that can make the difference. if you can hold your stack until the end i see it as a big advantage, i noticed that if a stack was still up in the last 20-15 seconds it had a good chance of staying up simply because everyone was focused on getting on the ramp.
our robot does have a stacker but we left it off at the Buckeye Regional because its not as efficient as we wanted it to be and in alot of matches its just too hard to pull it off, but if you can i think its worth it

[SkitzoSmurf]

Just got back from the BAE regional. Was great. I noticed that autonimous does make a big difference. The correct alignment of your robot could win the match. Aces High had an excellent program in which they went up, down went four stacks, and then another two with their big arm. Alot of teams just did a center plow, some were good enough to do multiple runs.
Alot of you are talking about the problems of stacking. One team that did it very effectively was 213, the dirty birds. They could steal, and then add onto it. was amazing. We have a modular robot, and our stacker part just had the hardest of times. You have to have that bin perfect, and if it gets bumped, BAMMM start all over. And a minute 45 is kinda hard to work with. BUT!!!, YES THERE IS A BUT!!!
I did notice the look of satisfaction on Dean Kamen's face when a team could successfully build a stack and defend it. Because that was what he designed the game to be about. It really pleased him to see teams take on the harder, more rewarding task, than just plowing around. I think it would be different if everyone concerned themselves with stacks, then plowing wouldnt be suckh a problem. I swear though, you think you have something, and a plow bot comes along, and it's gone. Stackers tend to tip alot too. . .

[Tonay K]

Here are my observations (I was there):

1. Don't even try and stack, it's useless.
2. If you have put extra traction onto your stock wheels to get grip, take them off! Stock wheels grip very well and all the extra traction will do is stall your motors (this is what happened to us, please don't make the same mistake)
3. The drill motors are pieces of crap. If a team didn't have problems with the drill motors, they weren't using them (ours fell apart in our hands)
4. The easy way to tell who builds their robot and who doesn't (engineers and mentors build) is to see who can still yell and cheer after 3 p.m. on the second day.
5. If you're in a smaller regional (35 teams or less), get your batteries charging and keep them charging. Match turnaround is extremely fast. (When you step off the field, you may already be on Final Call for your next match)

Please be prepared adequately. Our bot was not in great condition when we got there and we only got it working correctly for our last two qualification matches.

[David.Cook]

Well said, and I agree with you. I would prefer to be able to stack, and focus on building the point score rather than destroying it. Our students did not set out to create a stacker, so we are what we are.

I applaud the teams that designed the more difficult solution. Now we need a game that enables that solution to pay off as a valid strategy and have some reasonable chance of success. Please understand, I am not saying you shouldn't try to stack. I expect teams with well-designed stackers to win awards. What I am saying is that statistically speaking, stacking is an outlier. It will happen, but only rarely.

[Rook]

Unless a stacker can stack faster than another bot can knock stacks down, then stacking will be useless. Sure some stackers will win a match here and there, but it's just too easy to knock them down. Many of the bots that won the matches were nothing more than a square box on wheels. Perhaps if the stacks had to be built on a platform that holds the bottom box in place, then stacking would be more reliable.

Many people may not agree with me, but I liked the game in 2001 better. All 4 teams on the field were cooperating. The robots could do what they were designed to do.

[sevisehda]

Alot of teams who still support stacking argue it would swing the score by stacking a 2 or 3 stack. That doesn't make sense if you look at the stats. If you look at the match scores about half are within 25 points. Which means the ramp was the deciding factor in those matches. Solution in this situation, a purebred rampdom like the technokats. This would also stop the highway of traffic over the ramp. I counted on average 5 bots travle over the ramp throughout a match. This does not include hitting the wall or bots parking on it to finish.


Also why stack 2 or 3 when you could just defend a human player stack of 2, 3 or 4. I agree having a 4 stack is a key goal in a game. It's a waste of time to make a stack but you need a stack? Solution...Autonomous mode that lowrides under the bar and stops the bot near your 4 stack then defend it with your life for the next minut 45.

[bigk2k4]

We actually did have a match where a stack of 3 turned the match in our favor after all the stacks were knocked down and we need to rebuild one quick. We ended up having a battle for the top of the ramp, in which we both got knocked off. So the stack of 3 was the deciding factor... Wish it would've been earlier though...

By the way I loved your robot Sparky, I thought you guys were awesome!

[Hailfire]

How did all of the other stackers operate that made stacking take too long?

[DirtyBird213]

Relying on the human stackers to give 2 stacks of 4 was an effective strategy. We team 213 were able to effectively grab a stack of 4 and add to it. We also were able to transport up to 6 bins over the ramp. This made the stealing a part as well, if our opponent knocked down our 2 stacks of 4 we would steal their stacks. We also were able to create our own stacks. Time was of the essence tho. We were able to get 4,and we would sacrifice the ramp to protect our stack, out of 10 rounds our stacks were knocked down twice (once by ourselves) and once by the other team at the last second. Bin orientation was not a factor, as we have the ability to flip bins. The highest stack we made was 6 high.