[<<] [>>] by Stephen Mulliner
3rd September 2013 (Technical)

Golf Croquet Interactive Rankings

The Golf Croquet rankings can now be viewed in the same way as the Association Croquet rankings. Players can see their full playing history and records against other players as well as Event and Game listings. The URL is rank.worldcroquet.org/gcrank/rank.php [Aug 2019: now gcrankdg]

Many thanks are owed to Chris Williams whose involvement and assistance with this project was invaluable.

There is also a "modified Dynamic Grade" ("MDG") option which produces a ranking list based on a smoothed DG. This is experimental work in progress.

It should be noted that the minimum activity required for inclusion in the official ranking list has been changed and is now 10 games in the last 12 months which is the same as the AC requirement.

Rebasing

New Players

Rebasing is a normal procedure in both AC and GC for players new to the system. A provisional initial grade is given based on handicap or a subjective assessment of ability. This is then reviewed after 30 games. A performance grade is then calculated (based on the percentage wins and the average grade of the opponents) and, in AC, if this is more than 200 grading points different from the initial grade, the initial grade will be adjusted by 100 points. In GC, a similar approach is adopted but it is possible for some young players to improve very considerably over their first 30 competitive games and the rebasing required may be more substantial.

Unlike AC, GC has regularly experienced the arrival of new players of high starting ability. The recent inclusion of Egyptian domestic results has led to the addition to the database of several strong and previously unknown Egyptian players. Outside Egypt, strong AC players are usually able to take up GC at a high level. In these cases, the choice of initial grade is sensitive because of its effect on the upper reaches of the ranking list and the implications for selection and block seeding. It is important to monitor these players to ensure that any significant discrepancy between initial grade and performance grade is acted upon.

A general review of some Egyptian initial grades was also carried out in preparation for the 2013 GCWC based on the accumulated data provided by the Egyptian Croquet Federation since 2011. The main form of competitive play in Egypt is inter-club matches and it can take some time for a player to accumulate a statistically significant number of games.

Established Players

In AC, no established player had been rebased in recent years until July 2013. Most players enter the system at a low grade and any improvement tends to be gradual and is handled adequately by the normal operation of the grading system. However, Jose Riva (Spain) produced a strong performance in the 2013 British AC Opens and reached the quarter-finals. His grade of 1,900 was regarded as significantly unrealistic and he was rebased to 2,200. This was considered particularly necessary to ensure that the seeding of blocks in the then forthcoming AC World Championship was fair and realistic.

In GC, players sometimes return to competitive play after a prolonged absence at a level that is significantly different from their last results. Although this is more common than in AC, there have only been six such rebasings, one of which involved the 2011 World Champion, Mark McInerney. Prior to 2011, his last grade and index were 2,389 and 2,268 as at October 2006. During the 2011 GCWC, he won 24 out of 30 games with a performance grade of 2,864. In consequence, he was treated as a new player with a starting grade of 2,650, an index increase of almost 400 points. By the end of the event, his grade and index were 2,712 and 2,922. He played a further 22 games in winning an international event in early 2012, ending with a grade and index of 2,739 and 2,787 respectively and a performance grade for the 52 games of 2,761. Of the other five, four were upwards and one was downwards. A rebased player's former history remains in the GC database with "_old" added to the surname.