Is the qualification match robot randomizer really "random"

[Jared Russell]

With 41 regional competitions, it's going to happen that sometimes the best bots end up with and against each other consistently. The schedule generator takes a lot of factors into consideration, but robot ability is most definitely not one of them.

But yes, this year in Philadelphia it seemed that there was not a lot of parity in the schedule. The proof is in the pudding: the better robot were selected for the finals, including some with poor qualification records because of who they had to play against. Yet several top 20 seeds missed the playoffs altogether.

The scheduler doesn't have to be "rigged" in order to generate a match list without robot parity.

[Tom Saxton]

Originally Posted by Elgin Clock

With this paper I generated for the NJ Regional: ( http://www.chiefdelphi.com/media/papers/2224 ) I found that the placement of teams during qualification matches in the alliance stations were not equal.

The algorithm does try to balance each team's appearance on the red and blue alliances, but doesn't attempt to balance positions within each alliance.

The red/blue balancing was added because some event arenas are asymmetric where it's better to view the match from one end or the other, so it's a pain if your team is always playing from the less desirable end. The schedules generated before FIRST asked for that (before the 2008 season) were *much* more imbalanced red/blue than what it does now.

[GaryVoshol]

In five weeks of Michigan Districts, I have not noticed any clumping problems. This is especially significant given that there are 40 teams playing 12 matches each; obviously many see each other more than once. But that doesn't take away the perception - I heard of one complaint that they had to play with "that rookie team" (said disparagingly) 3 times. I hadn't noticed - and sure enough, a check of the schedule showed only one such pairing.

The only downfall with that size of events is the minimum match spacing has to be set to 3 - meaning sometimes a team barely has time to return to the pits before they are being requeued. But even that doesn't "clump" - if a team has a 3 or 4 game separation, likely there will be 11 or more games before their next match.

Good job, Tom.

[Elgin Clock]

Originally Posted by Tom Saxton

The algorithm does try to balance each team's appearance on the red and blue alliances, but doesn't attempt to balance positions within each alliance.

Oh, I definitely understand that.
All I ask is that for next year, (if possible) for it to be stepped up just a bit to include randomization within the red or blue as well a bit more.
What fun is advancing the program, if it will stay the same every year?
I guess I'm just an Engineer by nature (but not degree yet) and always want to see something improved. lol It's a curse... & a blessing all in one.
The jump from last year to this year's alliance pairing system was progress by leaps & bounds no doubt, and I congratulate you on that!!!
For next year, I only have that one request if possible with that said.
Just a suggestion!

Originally Posted by Tom Saxton

The red/blue balancing was added because some event arenas are asymmetric where it's better to view the match from one end or the other, so it's a pain if your team is always playing from the less desirable end. The schedules generated before FIRST asked for that (before the 2008 season) were *much* more imbalanced red/blue than what it does now.

I think the regional I went to this past weekend (CT Regional) is a perfect example of one of those where teams can play on the "less desirable end" as you noted.

The main screen which shows the field (and thus real time scoring, & video) is behind the Red Alliance station, so I can see where that request came from - Blue has an advantage in that scenario by being able to see the HUGE screen very nicely with a quick glace up forward, while the Red Alliance has a rather tiny LCD screen to glance over at in retrospect, or has to look behind the or rely on their coach to look behind them.

I guess it's true, every simple request has a good reason behind it!

[martin417]

I believe that the algorithm is written as fairly as can be achieved, given the limited number of matches teams play. However, I did see some oddities that caught my attention. The most unusual was one team that had a drive-train problem on arrival, and missed their first 5 matches (I saw many people from many teams lending a hand to get them up and running, FIRST at its best). They did send a human player for each match, and had very good alliance partners, so they were highly ranked, even though they hadn't had a robot on the field.

[Steven Sigley]

Why is there an emphasis on reducing matches with surrogate teams in the algorithim?

Because of time constraints at regionals?

I know i personally enjoy playing surrogate matches, you get to enjoy playing on the field without the personal stress that comes with losing a match.

[EricH]

Originally Posted by Steven Sigley

Why is there an emphasis on reducing matches with surrogate teams in the algorithim?

Because of time constraints at regionals?

I know i personally enjoy playing surrogate matches, you get to enjoy playing on the field without the personal stress that comes with losing a match.

Because if you've got too many with a surrogate, you're doing something wrong.

It's that teams like lots and lots of matches that count. Matches that don't count are a bonus. If you have too many surrogate matches, then you don't get those counting matches. Plus, if every team has a surrogate match, then why have a surrogate match at all?

[Ice Berg]

Back in 2007 (not relevant to this years match algorithm but still interesting) we were at the Trenton Regional, and we were against team 637 for every single one of our qualifying matches. This was definitely the least "random" case I have seen.

http://www.thebluealliance.net/tbatv/team/694/2007

[artdutra04]

Originally Posted by Ice Berg

Back in 2007 (not relevant to this years match algorithm but still interesting) we were at the Trenton Regional, and we were against team 637 for 6 out of our 7 qualifying matches. This was definitely the least "random" case I have seen.

http://www.thebluealliance.net/tbatv/team/694/2007

The 2007 algorithm was seriously flawed that year, and vastly different than the algorithm used in any other year in FIRST. That year, one team was randomly chosen from a low group of team numbers, one from a middle group of team numbers, and one from a high group of team numbers. As a result, there was a much more limited sample size of available teams in the algorithm, leading to match schedules with many of the same teams constantly playing with or against each other, and no one else.

[waialua359]

Originally Posted by artdutra04

The 2007 algorithm was seriously flawed that year, and vastly different than the algorithm used in any other year in FIRST. That year, one team was randomly chosen from a low group of team numbers, one from a middle group of team numbers, and one from a high group of team numbers. As a result, there was a much more limited sample size of available teams in the algorithm, leading to match schedules with many of the same teams constantly playing with or against each other, and no one else.

I agree.
We went to NJ that year and played Miss Daisy 4 times and Robotic Plague 3 times. We had a total of 7 matches.
My only complaint is that we went to NJ to meet many new teams. Why go through an entire weekend only to meet a few.
This happened though in '08 also for a few regionals. In Chesapeake '08, we saw the Robo Raiders (75) 4 matches in a row. 3 Against and 1 with them.

[Tom Saxton]

Originally Posted by waialua359

My only complaint is that we went to NJ to meet many new teams. Why go through an entire weekend only to meet a few.
This happened though in '08 also for a few regionals. In Chesapeake '08, we saw the Robo Raiders (75) 4 matches in a row. 3 Against and 1 with them.

Given a finite amount of time to generate the schedule, no schedule will be perfect. In the Chesapeake '08 regional, 75 and 359 were the only pair of teams that saw each other 4 times, all other pairs occurred three or fewer times. Even those two teams saw a total of 30 (359) or 32 (75) different teams.

Last year's implementation did a poor job of guiding the scorekeepers in choosing the minimum gap between matches. In the case of Chesapeake '08, that parameter was set too high (8) thus the scheduling algorithm was overly constrained. Because of the constraint to give teams at least 8 matches between rounds, the order of teams could not change very much from one round to the next. This caused excessive duplication among pairings at several of the larger regionals in 2008, and was not brought to my attention until I was waiting in the Houston airport for a connecting flight to Ecuador which kept me out of the country until after Atlanta.

That problem was fixed for this year. For example, the Chesapeake '09 regional had a minimum gap between matches of 4, and the resulting schedule was much better, with just two pairs that appeared 3 times and all other teams never seeing another team more than twice.