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Unread 13-06-2007, 22:13
Lil' Lavery Lil' Lavery is offline
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Re: [FVC]: Analysis Shows Improvement Possible in Ranking System

My general point about defense was that his formula didn't factor in defensive play properly to create an accurate simulation. In many situations, a defensive team will not score a single point, but can have a MASSIVE impact on the match as a whole. It is also impossible to quantify the value of a defensive bot (even as the person setting up the experiment), because the value of that bot changes each and every match, based on the offensive bots it is facing. A purely defensive bot cannot possibly have a value any higher than the combined value of the two offensive bots it is facing (ie, it cannot negate more points than they can score). In addition, a defensive design may or may not be effective against all offensive designs (ie, some bots this year were excellent at defending the high goals, but couldn't scoop balls out of the low goals and vice versa). Or the situation four purely defensive bots (not capable of scoring, which is possible, particularly if the scoring method is rather complicated or difficult, such as the FRC objective this year) are in a match against each other, the result is guaranteed as a tie (something not addressed in his simulation).
Quote:
Originally Posted by 1885.Blake View Post
Bill does not recommend interacting with the same three teams all the time.

Bill suggests a quick 3-match mini-tournament for a first group of four FVC teams; followed by another 3-match mini-tournament for a different group of four teams, followed by …. until all teams have played in a mini-tournament. Then you scramble the teams and do it again... until time runs out for the entire tournament. In each/any mini-tournament the teams would be matched up like this:
Match 1 AB vs CD
Match 2 AC vs BD
Match 3 AD vs BC
You can see that in any given mini-tournament, a team never has the same ally more than once and faces an ever changing opposing alliance in the three matches (played in rapid succession).
Even though you only have the same partner once, you still interact with the same three other teams three matches in a row. In a six match tournament (fairly large by FVC standards), you will interact with only six other teams out of the entire field during qualifications. The reaction to the FRC events of this past season suggest that the FIRST community would not accept this (look at the multiple threads about the scheduling algorithm for the 2007 FRC season), and in addition, those same threads suggest that the FIRST community favors random match generation (in terms of teams participating, they still value space between matches).
Quote:
Originally Posted by 1885.Blake View Post
Bill has not necessarily suggested it to the FIRST community as a whole. The strong implication of his original message is that FVC tournaments might benefit from using it. Even if he had recommended it to all of FRC, FVC, FLL, JFLL; I think it is a bit presumptuous for you to assert that “the FIRST community” would dislike a method that could be proven to generally produce more accurate “top 8”s than current methods (and that is likely to be no worse than current methods in extreme situations).

PS: The results of the math will not change if they are posted at some other time or under a more high-falootin heading.
A similar argument could be used for the scheduling algorithm put in place for the 2007 FRC competition, which seemed to be designed to create more competitive matches (a good thing right?). The FIRST community reacted with disgust to this, and especially its side effects which limited the amount of others teams that teams got to interact with (ask 1504 how they felt about facing 25 four times in Atlanta). FIRSTers, or at least those on CD, have shown a desire to play with as many different teams as possible on more than one occasion in the past.
Quote:
Originally Posted by 1885.Blake View Post
If I understand it correctly, Bill’s approach does not attempt to do this. Bill assigns the alliance’s score to the robots in the alliance. He uses a running total of these points to rank the robots at the end of a full tournament. He does this instead of assigning 2 qual points to each robot on a winning alliance.
While his scheduling method doesn't base teams on individual performance, he also gave math showing that a more proper ranking would be based on individual points scored, which, as I said, would be next to impossible, and would discredit defensive efforts.
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