Computer generated initial alliances

[katkimball]

What are the criteria the 2014 FRC algorithm uses to generate the initial team alliances? Is it different District vs Regional events? Does it factor in a District win by aligning a team with a district win with lower ranked teams for the second play? I can only find data on the web for the 2008 algorithm and that must have changed as we were against the same team three times in only 12 rounds so “Minimum possible number of times a team plays opposite any team” doesn’t seem to apply? Thank you for any assistance in finding this information.

[Steven Donow]

Per section 5.3.2 of the manual:

The Field Management System (FMS) assigns each Team two (2) ALLIANCE partners for each Qualification MATCH using a predefined algorithm. The algorithm employs the following criteria, listed in order of priority:

Maximize time between each MATCH played for all Teams
Minimize the number of times a Team plays opposite any Team
Minimize the number of times a Team is allied with any Team
Minimize the use of SURROGATES
Provide even distribution of MATCHES played on Blue and Red ALLIANCE

All Teams are assigned the same number of Qualification MATCHES, unless the number of Teams multiplied by number of MATCHES is not divisible by six. In this case, the FMS randomly selects some Teams to play an extra MATCH. For the purpose of seeding calculations, those Teams are designated as SURROGATES for the extra MATCH. If a Team plays a MATCH as a SURROGATE, it is indicated on the MATCH schedule, it is always their third Qualification MATCH, and the outcome of the MATCH has no affect on the Team’s ranking criteria.

A team's perceived skill/history has no impact on the schedule.

[Chris_Ely]

Game Manual, Section 5

Originally Posted by 5.3.2 MATCH Assignment

The Field Management System (FMS) assigns each Team two (2) ALLIANCE partners for each Qualification MATCH using a predefined algorithm. The algorithm employs the following criteria, listed in order of priority:

Maximize time between each MATCH played for all Teams
Minimize the number of times a Team plays opposite any Team
Minimize the number of times a Team is allied with any Team
Minimize the use of SURROGATES
Provide even distribution of MATCHES played on Blue and Red ALLIANCE

All Teams are assigned the same number of Qualification MATCHES, unless the number of Teams multiplied by number of MATCHES is not divisible by six. In this case, the FMS randomly selects some Teams to play an extra MATCH. For the purpose of seeding calculations, those Teams are designated as SURROGATES for the extra MATCH. If a Team plays a MATCH as a SURROGATE, it is indicated on the MATCH schedule, it is always their third Qualification MATCH, and the outcome of the MATCH has no affect on the Team’s ranking criteria.

[Schnabel]

Check this out.

[katkimball]

Thank you Shnabel FRC #0314 for the link that answers so many questions!

I was sure there was a different algorithm for district events as we had 36 teams and 12 matches so no surrogates and yet played against the same team 3 times and never played with at least 4 teams.

I now see there are other factors that figure in to the equation.

[Caleb Sykes]

Originally Posted by katkimball

Thank you Shnabel FRC #0314 for the link that answers so many questions!

I was sure there was a different algorithm for district events as we had 36 teams and 12 matches so no surrogates and yet played against the same team 3 times and never played with at least 4 teams.

I now see there are other factors that figure in to the equation.

emphasis mine

does "played with" as used here mean "played on the same alliance as" or "played in the same match as"?

[alectronic]

Originally Posted by katkimball

I was sure there was a different algorithm for district events as we had 36 teams and 12 matches so no surrogates and yet played against the same team 3 times and never played with at least 4 teams.

The algorithm is the same for all events, but when there are so few teams and so many matches at districts, the likelihood is simply that you end up playing with/against the same teams more often than a traditional regional. The FTAs at each event review the schedules after generating them, and review the number of times each teams is paired with/against teams and maximize the number of opponents and partners, per the rules quoted previously.

[engunneer]

Keep in mind that there are some inputs when the program is run, and (not applicable to your case) any surrogate matches don't count against the partner/opponent duplication score.

[katkimball]

Yes I mean played on the same alliance as

[Caleb Sykes]

Originally Posted by katkimball

Yes I mean played on the same alliance as

In that case, I am not surprised in the slightest. Since you are only partnered with 2 robots/match, and you play 12 matches, you only play on the same alliance with a maximum of 24 robots at a 12-match event. Since there were 35 teams at your event that weren't you, this means that you will not play with at least 11 of them in quals, no matter what the algorithm is.

[Chris is me]

I also noticed that 2791 played with / against the same teams a ton of times at Finger Lakes. Events that large normally have less repeats. Other teams had a lot of repeats as well.

We played with / against 341 three times (1/2). We played twice against 1126. We also played 1 with and 1 against teams 20, 1592, 174, 1450, 1551, and 3173. Not that upset about it or anything, just thought there was a bit less emphasis on playing unique teams this year than prior years.

[Electronica1]

Originally Posted by Chris is me

I also noticed that 2791 played with / against the same teams a ton of times at Finger Lakes. Events that large normally have less repeats. Other teams had a lot of repeats as well.

My team also noticed more with/against repeats than usual at our events this year. Even at the VA region which is a 64 team event. It was kind of odd.

[MikeE]

The scheduling algorithm focuses on minimising repeated alliance partners while also trying to limit the number of repeated opponents and the number of times you see the same teams in either role.
While the algorithm is great for standard regional events (50+ teams and around 10 matches) and gives a reasonable schedule for all events, it struggles a little when the number of teams is between 2 & 3 times the number of matches per team.

[MrTechCenter]

Originally Posted by katkimball

Thank you Shnabel FRC #0314 for the link that answers so many questions!

I was sure there was a different algorithm for district events as we had 36 teams and 12 matches so no surrogates and yet played against the same team 3 times and never played with at least 4 teams.

I now see there are other factors that figure in to the equation.

I used the algorithm to generate a match schedule for an event with just 22 teams at it. Worked fine in making sure that teams did not get the same alliance partners/opponents too many times, and that was to my surprise, I expected that teams would have to play with each other several times because of how few teams there were, but this was not really the case. However, some teams had to play back-to-back matches.

[GaryVoshol]

If the minimum match separation parameter is set too high, then there will be more repeats of teams seeing each other in matches. For example, in that 36-team event, if minimum match separation is set to 6, the exact same robots will be forced to play in matches 1, 7, 13, 19, etc. (I wouldn't be surprised if the software has limits that wouldn't allow you to enter too high a value in the parameter.) As in the example of the 22-team event, to get more mix in the matches, the minimum had to be set low and allow back-to-back matches.