SoCal 18 & Over Sectionals may be another unflighted round-robin disaster

It is the time of year that Sectionals begin to be played, and some sections elect to use the the unflighted round-robin format to identify the teams to advance to a single elimination bracket.  In this format, each team plays the same number of matches against random opponents, and then the top-2 or top-4 teams advance to a final or semi-finals.  USTA National began using it several years ago, and more sections are using it for Sectionals when the number of teams they have doesn't nicely fit into an even number of sub-flights.

The major problem with the format is that when not done correctly, there is a chance of a team going undefeated and not advancing.  The way Nationals is run with 17 sections and each team playing four matches, there is usually a very small chance of it happening, and it has come close to happening twice but hasn't yet.  However, the way some sections implement it there has been a far higher chance of it happening and it has happened at least once in NorCal.

The typical problem is having too many teams not playing enough matches.  In NorCal's case they've had over 20 teams in some flights and played just three matches.  That is a recipe for disaster and a 5th place team that was undefeated got sent home.

Well, it appears it may happen again this weekend.  SoCal is holding its 18 & Over Sectionals and is using unflighted round robin with too many teams and not enough matches.  Specifically, using my simulation of the round-robin, the problematic levels are:

• 3.0 Women - 14 teams playing 3 matches for 4 spots - More than 3% chance of 5+ undefeated.
• 3.5 Women - 17 teams playing 3 matches for 4 spots - More than 5% chance of 5+ undefeated before the event, part way through it is now over 42%!
• 4.0 Men - 10 teams playing 3 matches for 4 spots - Less than 1% chance of 5+ undefeated, but there is a chance.

The other levels are either in sub-flights or don't have too many teams.

The 3.0 women and 4.0 men have very slim chances of it happening, but we will see how the 3.5 women finish up, but I think there is a good chance an undefeated team is sent home!