Match Pairings not random (not even close!)

Did any of the other regionals have really messed up qualifying pairings? At St. Louis, we had one team on the opposing alliance 4 times! Also, we had one of our matches duplicated (exact alliances)!

I’m sure that this led to some nuances in the qualifying points, for a number of reasons.

If the opposing alliance had a robot (or two) that could not get over the ramp, the scores tended to be very low as the totes got bulldozed out of scoring position. Plus, with no ramp points for the losing alliance, the 2x adders didn’t amount to much. In many ways, you were better off where the teams were good enough to get over the ramp and make some points.

We were fortunate enough to qualify well, but it’s really hard to figure out if we did that based on skill, or just dumb luck! I hope that they get the random number generator restarted before the next round of regionals. I feel sorry for some of the teams that had frustrating qualifying because of the non-random pairings. Everyone should have 8 different matches to give them an opportunity to show their stuff!

At BAE I think they did an excellent job gettign us random parings and spreading out the matches as much as they could, we had matches 11, 22, 30, 40, 50, 60, 70, 80, 90, and 100 You really cant get much more spread out than that over two days with 44 teams competeing, as for pairings, there was problay one or two teams that we went aganist twice but that was it

i saw that brr and grr were allied together twice on saturday at the Ohio regional. kinda like nationals last year when we didn’t see 50 of the teams in our division on the feild with us

At VCU, we had 3 identical matches. The same robots were on the same teams. To top it off, we wire tied our auto. switch in the right position because until elimination rounds, we were on the red alliance, on the right hand side. If that is random pairings, I need to go buy a lottery ticket…:wink:

I think Techno Jays at Buckeye were probably pretty sick of being our opponents after 3 matches!?

My experience is that the matches are too random. In the past I’ve had 2 matches back to back on the same day. Another day we didn’t have any in the morning all were in the afternoon. The program is propobly a simple spreadsheet that only makes sure teams have the same number of matches. They could add more checks to insure duplicate matches don’t occur, teams have at least 2 match breaks. It’s all how much effort FIRST puts into the schedule. As for being Red all day, does that really matter? Its normally worse in smaller regionals because the lack of a pool to draw from. The larger the pool the less problems the schedules seem to have.

At BAE, our actual matches were very random, but during practice, we ended up being pared with Buzz every time.

At SLR (55 or 56 teams) we were partnered with 1215 twice in one day. We were opposed by 1005 twice, 1098 twice, and 770 four times!

-Joel

Actually, it really is not as easy to pare up the matches as you think. While i don’t know how first does it, I talked with the person that made matches for a local robotics competition, and it’s pretty hard to make them.

If you logically think about it, it’s very hard to make a match list.

First: Are you going to assign matches to teams, or teams to matches. (IE: Are you going to loop through the team list and assign teams to matches, or are you going to loop through the empty match list and pull teams to fill that match)

Second: Now you have to insure that teams aren’t going to play all back to back, but rather spread out though all the matches. (IE: For team fill: Pick match # between 1-10. Pick match # between 11-20 (and make sure that if the match is 11, that the last one wasn’t 10). For match fill: Go through the first 10 matches, and pull numbers only once from a team list. Make sure that none of the teams that were in match 10 play in match 11)

Third: Attempt to prevent teams from playing with another team more than once. (IE: Have different alliance partners each time)

Forth: Make sure that the script doesn’t time-out or not find a solution that passes all requirements.

As you can see… it’s not as easy as you may think from a programming viewpoint as you may think.

<sort of off topic>Making lists like this really is quite hard. (Even to programmers, I first looked at making match lists and thought “This isn’t hard”, but once you get down to doing it… it’s a pain in the butt. I’ve thought about it a few times, but really don’t even want to know how something as large as my high school makes the class schedules. - There are sooo many constraints</>

at manchester in THREE matches we were paired with a partener we had allready been allied with previously. and in one match were against a team we had allready played against as well.

AT BAE we were paired with the same three robots in 6 out of our 10 matches. It does make it easy to startegy plan in second match but we did not even see 6 of the top ten finishers!

we had the same partner 2 of our practice sessions and we went up against the killer bees our last 2 matches.

It would have been nice to have variety but it wasn’t that big of a deal.

Its just the way things turned out and we dealt with it.

Random number Generator V1.0
Starting random engine…
Buffering for output…
Random number stream:
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9

– End Output

The problem with random numbers is you never know.
Greg

*Originally posted by Nataku *
**i saw that brr and grr were allied together twice on saturday at the Ohio regional. kinda like nationals last year when we didn’t see 50 of the teams in our division on the feild with us **

it was actually 3 times & we had to play against them once. 2 out of our first 3 matches were against the same 2 teams. FIRST had better fix this fast or there will be alot of unhappy people. & BTW It was us that 461 was paired with for practice & we only played 1 team in the the top 10. The eventual #1 seed. We did beat them in one of the 2 times we played them.

The problem that FIRST has is that their top priority is that teams have enough time between matches (approx. 1 hour) to repair and refine their robots. The problem is that since your next match is in about an hour, and all the teams you played with have their next match in about an hour, odds are pretty high that you will see at least one of them again in your next match. If FIRST actually went through and made sure that pairings were never repeated, the schedule would actually be less random.

Think of it this way: If you flipped a coin ten times, but wanted to make sure that you never had two heads or two tails in a row, there are only two possible combinations (hththththt and ththththth). However, if you had no checks on the results, there are 1024 possible combinations. Obviously, the first scenerio is much less random.

This “non-randomness” has been a perennial problem with FIRST teams for years. The competition software apparently automatically generates the pairings. With small data sets the randomness goes away (10 rounds- 50 teams).

Of course doing it by hand is a nightmare. Believe me- I’ve done it using both techniques. Even worse is trying to keep any team from playing matches too close together.

Perhaps a good off season project is for someone to make the perfect system without assigning team numbers and present it to FIRST. Make a number of possibilities for 40-41-42 teams etc- so FIRST can use whatever system is applicable to the regional based on attendance.

Of course someone will always have a problem with it…

WC:cool:

*Originally posted by rees2001 *
**it was actually 3 times & we had to play against them once. 2 out of our first 3 matches were against the same 2 teams. FIRST had better fix this fast or there will be alot of unhappy people. & BTW It was us that 461 was paired with for practice & we only played 1 team in the the top 10. The eventual #1 seed. We did beat them in one of the 2 times we played them. **

It happened to us with 1000. A good team to be matched up with. A tough team to be matched up against.

St Louis is the first regional we have attended in the past four years where we had such non-random pairings. I know many other teams had similar pairings at STL.

In the past, either someone hand-paired or set the flags in the s/w differently. I’d be curious to find out why it worked in teh past but not this year, since this kind of program shouldn’t change from year to year.

Part of the problem with non-random pairings is that you only get to interact with a small segment field. There are competitive issues as well. But they are not as major as the interaction issue.

There were other technical difficulties as well in STL, especially with the scoring program. I suspect that in the first weekend of regionals that all these bugs cropped up and there simply wasn’t enough manpower to deal with everything.

It really depends. I was at the VCU regional, and some teams had problems with the psuedo-randomness of the match pairings, while others did not. Our team happened to be against team 401 twice, but that is all, and we didn’t find anything wrong with that.

Also, this does come up every year. One of our mentors knows the guy who does the match pairings for a few of the regionals, and he explained it this way: they do the pairings the night before competition for security reasons (they don’t want anything leaked), and that doesn’t give them enough time to change anything drastically. Also, due to their system setup, it is impossible to individually switch teams by hand (and even if they did, the issue of just how many repeats are allowed, and who to switch with comes up).

Overall, it’s an imperfect system. Any system will be. The people behind it are a bunch of die-hard FIRST volunteers, who are doing their best to create a fun playing enviornment. If you do have problems with match pairings, I only ask you to bring it up in a polite way, and don’t expect them to change things this year.

Good luck at all your regionals everybody!
Stephen

we also had similar pairings, we were on the field with a team 4 times,another 3 times and others twice. it wasnt that big of a deal to us, yes it did hurt our rank though, but i really would have liked to be able to play with and against a wider variety of robots.