In the grade levels at competitions, Beginner - Prizewinner, each dancer is given a mark out of 100 by his or her adjudicator. Each adjudicator has a slightly different “scale.” For example, for one judge, 85 might be the highest score they give out, whereas another judge might be more generous and give their top dancer a 95. The highest mark wins, second highest is awarded second and so on.
But in Championship and Oireachtas competitions, a dancer is graded by three adjudicators and their championship result is based on all three dances. If you have three judges and they each give each dancer a score out of 100 based on a personal scale, it becomes a mathematical nightmare backstage to add and average every judges score for each round.
To make tabulating easier, each judge’s marks (raw scores) are converted into corresponding “Irish Points” using a chart created for commission competitions. The Irish Points are vaguely logarithmic, in that 1st place= 100 points, 2nd place = 75, 3rd place= 65 etc, until 50th place = 1. This gives higher marks by single judges more weight than average marks by more judges. In other words, if a dancer gets a first place from one judge somewhere, it will increase their overall placing in the competition by a surprising amount. Conversely, this gives dancers that get a first place from two judges a higher lead than a dancer that was only placed first by one of the judges.
For example, in a 3 judge competition it is almost impossible to Not get first with 2 judges agreeing that 1st place is warranted, since with 200 Irish points, the 3rd judge would need to place a dance 7th or worse to overcome the 25 point bonus between 1st and 2nd. This scoring method helps ensure that a single bad adjudicator does not unfairly ruin the results. At a standard 3 judge Feis competition, a unanimous 1st place score is 300 (100 from each judge). At Regional Oireachtas competitions, there are 5 judges who rate all three dance programs, creating the possibility of a perfect score of 500. At the World Championships (Oireachtas Rince na Cruinne), there are 7 judges, which means that 700 would be perfect if all 7 judges agree that one dancer performed the best.
Thank you to www.mjpacademy.com for this great explanation.