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View Full Version : Quantitatively Evaluating the Regionals


Nemo
12-04-2011, 19:05
Now that all of the regional and district events are finished for 2011, does anybody have a favorite way of evaluating which ones were the toughest to win?

This is a fairly complicated question, despite an obvious answer (Michigan State Champs) and some conceptually simple possible methods (ex: total average points per match).

I'm toying with this problem for fun, and initially I'm looking at ways to compare the OPR data from regional to regional. For example, one can reason that the high scoring teams have the biggest impact on regional difficulty, and thus calculate OPR minus some threshold for each team, sum that up for the whole event, and in this way determine how much big scoring is present at a given event.

I am also interested in the impact of having different numbers of super strong and fairly strong teams present. For example, having just one super powerhouse doesn't make an event really hard to win, because then you can win by getting picked. Having two of those super teams makes it really hard for everyone else, but fairly easy, relatively speaking, for those two teams, even moreso than if there was only one super team. That's assuming they aren't opposed to being allied together.

But there are other things going on as well. If it's a big regional with lots of teams, then it's slightly harder for the two super teams to win, because a third team might go undefeated (not facing either super team) and have a higher qualification score, then go onto prevent the super partnership. Also, a regional with exactly 2 super teams, 21 solid teams, and 30 really weak teams might be a bit harder for the super teams since they'd have a weaker 3rd robot than opposing alliances and would have to fight through 3 stacked alliances to win.

Another angle to consider this from is that the percentage chance of winning a given event is going to depend on your team's robot ability, represented by OPR or some other measure. Obviously a higher OPR will give you a better chance to win any event... or would it? In the event with two super teams, you might be better off with a medium OPR than a higher OPR, because you'd have a better chance of landing on the top alliance with pick #16. Also, I can envision a pair of events where a higher OPR team would be more likely to win event A than event B, while a medium OPR team would be more likely to win event B than event A. For example, let's say two events already have 3 super strong teams registered, but one has a really deep pool of solid robots in its second tier, while the other only has a couple of solid tier 2 bots. I think the medium OPR team is better off with the deep pool in hopes of either being a 3rd pick or getting on a stacked alliance; in the other event, the medium team is more likely to end up as an alliance captain without any really strong teams to pick as partners. The super team, on the other hand, is probably more likely to win the event with 3 strong robots and a sharp dropoff after that. They can expect to end up on one of two strong alliances and get their chance to duke it out in the finals with the other strong alliance.

Anyway, given that difficulty depends on your team's OPR, I think it would be cool to have an algorithm that could output the percentage chance of winning for a mystery team with a given OPR that joins at the last minute.

I know that I'm missing a lot of important considerations here. I just think this is an interesting problem to examine. It must be because I'm a baseball stat nerd.

The Lucas
12-04-2011, 19:38
Ed Law calculates OPR across all events (all matches, one matrix) in his scouting database (http://www.chiefdelphi.com/media/papers/2174?). It is on the WorldRank tab. Check it out, it does change the OPR significantly.

For instance here is the OPR data I was using going into Philly last week:
Philly Teams by highest single event OPR
395 37.475 NY
365 33.9129 MD
341 26.0867 FL
486 23.7777 NJ
56 22.9167 DC
103 21.2299 FL
834 20.1278 NJ
1302 19.2485 NJ
3015 18.6522 ROC
1403 16.4453 MD
1143 16.1828 MD
2534 15.9369 DC
1647 14.8564 NJ
816 13.8934 NJ
272 13.8589 NY
303 10.9292 NJ
1980 10.724 MD
2234 10.2987 NJ
1640 9.86629 ROC
316 8.89519 MD
2729 8.60878 NJ
369 8.03446 NY
102 6.69432 NJ
3123 6.59455 DC
223 5.84058 NJ
2607 4.57833 NJ
1517 4.53616 NH
224 4.1761 NJ
2641 3.88772 PIT
225 3.00393 MD
1391 2.3401 NJ
484 1.85067 MD
2053 1.77439 ROC
433 0.239089 DC
423 -0.89371 NJ
1370 -2.85469 MD
204 -3.86119 MD
708 -4.59569 MD
2895 -6.02996 NY
3182 -6.6021 CT
87 -7.83013 MD
709 -7.85528 NJ
203
304
321
357
1495
1712
1791
2229
2539
2559
3151
3167
3553
3629


Philly teams by WorldRank OPR
365 34.49753988
395 28.12398837
56 27.60206962
341 24.29760008
103 23.33148775
1143 22.87816165
2534 22.51985178
1403 21.13740269
1302 19.92360914
486 19.10922384
834 18.74439376
1647 18.14687306
272 16.36615124
3015 14.28577685
816 13.25102034
303 12.45179496
2234 11.43519307
1980 9.801092345
369 8.987250719
1640 8.695600056
316 8.526063969
3123 6.615008499
223 6.016749535
2729 5.878076428
102 5.156151462
224 4.924877745
225 4.92132435
1517 4.867728693
2607 4.242186796
1391 2.211706164
2053 2.032134126
2641 -0.493929277
433 -0.894736634
423 -1.186731875
484 -1.247363326
1370 -3.46124594
204 -4.21698992
2895 -4.888207753
709 -5.031536874
708 -5.820604497
87 -6.332812955
203
304
321
357
1495
1712
1791
2229
2539
2559
3151
3167
3182
3553
3629


Again this is old data, so go look at the new data in Team 2834's database.

Racer26
13-04-2011, 10:11
Empirical evidence of 2 high-OPR teams against a handful of medium OPR teams and a bunch of low (or negative) OPR teams: GTR and Waterloo since 2007.