**FIRST EMAIL**/Updated Alliance Pairing Algorithm

[ChrisH]

For all of 330's years, we have felt really wierd on the rare occasions when we were not in Match 1 or 2. This began long before people started messing with the algorithm. In fact, NOT being in the first match was the only thing we liked about last years's pairings. Sometimes random things are just random, they only look like there is a pattern.

Before the match schedule is locked in, it can be "audited" to see how many different teams each team will play with and against. If there are "too many" repeats, then the algorithm can be run again. But it takes 10 or 15 minutes each run and the Field Management System can't be doing anything else during that time. If you have to run it more than twice, you can forget handing out match schedules at lunch time. In fact, the scorekeeper and FTA can forget lunch altogether.

There is a lot af variability in the performance depending on the constraints. If you have 48 teams and tell it you want 7 matches between times a team plays, then you only have 6 options for opponents and partners. A match schedule set up this way will have a lot of repeat teams. On the other hand, if you set it for 3 matches between times a team plays, then you have more sets of three opponents than you have matches. The algorithm is very sensitive to this and it takes some experimentation to get it right.

At the LA regional the fewest number of unique teams a team faced was 24, the maximum was 27, the average was somewhere between those two. ( The number of unique partners for every team was 18, the maximum except for surrogates, they had 30 oppponents and 20 partners). But we purposely set the minimum time between matches very low. I forget if we used 3 or 4. This guaranteed teams a minimum of 18 minutes between matches. Since a round took 8 matches to complete, the maximum time between matches was 90 minutes. This is typical of our experience under the pre-2007 algorithm. In actual practice I believe the average time between matches was more like 45 minutes, with very few, if any having turnaround times that short or long.

The best thing to do is set the minimum time between matches fairly low and let the algorithm sort out which schedule gives teams the most time between matches. It will probably pick a schedule within 5% of optimal.

Originally Posted by Travis Hoffman

So................

How has the new alliance pairing algorithm treated you so far this season?

I still notice some repetition - are regional staffers correctly parameterizing the algorithm to yield optimal results?

http://www.thebluealliance.net/tbatv/team.php?team=48

Personally, I'm rather agitated and puzzled by the fact that 48 has been stuck in Qualification Match #1 at 3 different regionals, regardless of whether we are the lowest numbered team there or not. At Midwest, 33 didn't even play til Match #5, so it's not like all the lowest-numbered teams are stuck in Matches 1-3.

One begins to wonder if this rather annoying fate is intentionally being forced upon us, given the supposedly random nature of this year's algorithm over last year's...... It's a running joke with us to predict, accurately, that we're in Match #1 at every event we attend, and find out later that we are correct.

After last year, where the Algorithm of Death pretty much forced us to be in one of the first three queued matches, it's GETTING OLD. I'd prefer not to be queued up as soon as we get to the venue on Friday, just for ONE TIME. Is that too much to ask? Perhaps in Atlanta we can have a bit of a break? Cuz, ya know, sometimes it's nice to be able to get a breath in and perform functional checks and such without having the event pit announcers breathing down our necks as soon as we walk in. K? thx, bai.