Another unflighted round-robin disaster in the making at SoCal 40 & Over Sectionals

Southern California will be holding their Sectionals for the 40 & Over division in a few weeks, and once again the unflighted round-robin format is being used in a way that could likely result in an undefeated team not advancing.

I've written numerous times on the subject of the risks and occurrences of undefeated teams being sent home, so I won't go through them all again, but suffice it is to say, it has happened and the chances are often pretty good it will happen for a given event.

National uses the format for Nationals, and with 17 teams and four matches per team, there is almost always a chance of it happening, but the chance is very low, often around 1% or less.  Still, even with that low a chance, you would expect it to happen every 75-100 events or so.

But what has been done by several sections is to use the format in an even riskier way, and that is what SoCal is doing.  The riskier use is to have more than 17 teams, and have them play only three matches.  When this is done it is even more likely you get "islands" of teams where many teams to play each other and they can all go 3-0.

As of my writing this, the teams/schedules could still change a bit perhaps, but:

• The 3.0 women have 14 teams playing three matches each.
• The 3.5 women have 17 teams, and the schedule isn't up yet but they'll likely play three matches each.
• The 4.0 women have 18 teams playing three matches each.

These are the risky flights, the others have fewer teams or have flights.

The 4.0 women is the worst, more teams than Nationals and fewer matches, a recipe for disaster.  If all the teams were equal, my simulation says there could be as many as seven (7!) undefeated teams and there is a 2% chance of five or more.

But the teams aren't equal, and in that case some teams are more likely to win, and my simulation says there is over a 6% chance of five or more being undefeated.  It isn't odds on to happen of course, but that is a reasonably high chance and once you'd think they would try to avoid.

This can be seen if we look at this diagram showing who plays against who.

For example, SDNC-Flynn, SD-Webster, CC-Braun, V-Schoenburg, V-Chao, SD-Dielman, and SDNC-Moses all don't play each other and could each finish 3-0.

The other two scenarios are not as bad.  The 3.0 women with 14 teams has a less than 1% chance of five or more undefeated.

We'll see what happens!