During a tournament yesterday I came across a rather strange bug. When hanging up standings during the final round, a player comes up to us to inform us that his resistance is listed as NaN. The player was in contention for prices so it was important for him to know the know the information, however in all honesty he should just win his match.

This aside, we started looking into calculating his “resistance” (OMW%) manually. Soon we find out that he got paired against a player round 1 that got an emergency call from his work and had to leave. We dropped him from the player list without entering the score of his match first. This resulted in WER believing that said dropping player had played 0 matches and possibly lead to WER trying to devide by 0 (which can lead to a NaN)

Luckily the solution was simple: Update the score from 2-0 to 2-1 and than back to 2-0 and WER listed the dropped player afterwards with 1 match (that he lost).

I believe this error can happen as well in following rounds, but it will not produce a NaN at that point, because the dropped player will have at least one game in this case. The moment I have my hands on a computer with WER I will test this specific case.

So if a player drops (for an emergency) I would advice against dropping him from the player list if his score of the current round is not given in yet!

Edited Niki Lin (Nov. 9, 2014 08:34:38 AM)

This is also just good tournament process, I feel; if you have paired for a round and a player has to leave before the round is started, or even mid round, he should be considered to have conceded and dropped from that match, rather than dropped from the player list. I suspect even if there is a bye at play this is the preferable method, as it keeps the mechanical details of the tournament organic.