Predictability of tournament results based on ratings.

2016 July 28 at 06:51 » Tagged as :scrabble, koth, pairing, vargs,

This is a part of a series of articles on the King Of The Hill Pairing System and it's use at Scrabble tournaments. King Of The Hill or KOTH for short is a strict 1 plays 2, 3 plays 4 , 5 plays 6 pairing system commonly used at the last few rounds of a Scrabble competition. It allows repeat pairing. In other sports it's sometimes used without repeats and then it's called Monrad, Danish Pairing, Australian Draw etc. This analysis is based on the results of the Sri Lanka age group Scrabble Championship 2015. As any Scrabble enthusiast will tell you, Sri Lanka is a power house for scrabble at the junior level, so the conclusions drawn here can be applied in other countries as well.

Pre tournament ratings are an excellent indicator of whether or not a player can be considered a contender for any of the prizes. Past winners of this event have been players with high ratings. The defending champion Hasindu’s rating was 900 at the time he won the event and he entered the tournament with a rating of 1053 which clearly indicates a significant improvement of his playing skill.

A total of 17 rated players took part in the event with the highest being Migara with 1148 points. These 17 players regularly compete against adults and beat them in rated tournaments. The rest of the field only participate in age group or inter schools tournaments which are not rated and the standard of competition is much lower. As a result There is a huge gap between the strengths of the rated and unrated players. 

Rank Name Rating Wins Position Difference
1 Migara Jayasinghe 1148 5 2 -1
2 Aabid Ismail 1134 6 1 1
3 Janul De Silva 1054 4 20 -17
4 Hasindu Arumapperuma 1053 4 13 -9
5 Janidu Karunarathne 964 3 38 -33
6 Thavalakshman Yoganathan 938 4 21 -15
7 Hayati Rassool 924 5 3 4
8 Radinka Dissanayake 897 5 5 3
9 Thirandi De Silva 847 3 37 -28
10 Vignesh Pirapaharan 840 4 15 -5

Table 2.7 Players sorted by rank vs their final position.

Only four of the ten highest rated players managed to secure prizes. As has been shown in 2.3 many of the players who missed out had to play more contenders than the prize winners. It will be shown in the ensuing sections that the pairing effectively prevented these players from winning any prizes.

In previous sections, we had already discussed how the draw had a huge negative impact on Janidu and Thirandi, but Thavalakshman is a special case. The draw did effect him by pitting him against 5th placed Radinka very early in the tournament. He might still have ended up in the top ten if he didn't suffer an unexpected defeat in the last round by just one point!