The Victory Briefs Rankings have been updated for the 2016-2017 season!
Our first update includes the results of Grapevine, Loyola, and Wake Forest. Our rankings use last season’s results as a starting point for debaters competing again this year.
Congratulations to Samuel Wood and Harish Korrapati of Ardrey Kell High school, and Jack Wareham of Oakwood, for starting out the season on top of our PF and LD rankings, respectively.
We are also excited to announce an update to our ranking system for this season! This year the algorithm used for our rankings is the Glicko-2 ratings system, which is an updated version of the Elo system used last season.
While the two systems are quite similar, Glicko-2 system weights the effect of each round based on the reliability of the ratings of each debater. This change will correct for problems that arise in Elo when some teams compete in rated tournaments more often than others, or have competed much more recently.
The problem with the Elo system that the Glicko system addresses has to do with the reliability of a player’s rating. Suppose two players, both rated 1700, played a tournament game with the first player defeating the second. Under the US Chess Federation’s version of the Elo system, the first player would gain 16 rating points and the second player would lose 16 points. But suppose that the first player had just returned to tournament play after many years, while the second player plays every weekend. In this situation, the first player’s rating of 1700 is not a very reliable measure of his strength, while the second player’s rating of 1700 is much more trustworthy. My intuition tells me that (1) the first player’s rating should increase by a large amount (more than 16 points) because his rating of 1700 is not believable in the first place, and that defeating a player with a fairly precise rating of 1700 is reasonable evidence that his strength is probably much higher than 1700, and (2) the second player’s rating should decrease by a small amount (less than 16 points) because his rating is already precisely measured to be near 1700, and that he loses to a player whose rating cannot be trusted, so that very little information about his own playing strength has been learned.
With this change, the Victory Briefs Rankings will once again be the most accurate, and evidence-based ranking available for PF and LD debate.