You are correct.  Simply re-word your rule to be, "When fewer than seven races have been completed, no scores shall be excluded."  Done!

Appendix LG contains the suggested wording :  https://www.sailing.org/tools/documents/2021AppendixLG28112020-[26802].pdf

This kind of error can be amusing - for instance when it is stated that 1 race is needed to complete a series, and,due to difficult conditions, only one racie is sailed.
So, there is a series, so the worst score is excluded and everybody wins!

Yes, the worst race is dropped, but RRS A8.2 will break the ties.  

The concerning part of this is that I saw this wording in a set of SIs I was reviewing. When I suggested that the wording be changed, the response was that the wording was the same as what is used by US Sailing. I pulled up a set of SIs for a recent US Sailing Championship Regatta and the wording I used above is pulled directly from those SIs.

Also, since the rule (A2.1) provides for a different arrangement of excludable scores, you are not changing the rule by making such an arrangement.  The wording should be, "In accordance with RRS A2.1, a boat's series score shall be the total of her race scores excluding her worst score only after seven (7) races have been completed."

The language in Appendix LG is far too wordy for my liking - and the fewer words there are, the more likely they'll actually get read. "Sailors are smart people who do not read." - Tom Duggan

Matt,
Your wording does not define how the series should be scored if less than 7 races are completed. Therefore we would need to look at A2.1, which says the worst race is excluded. We are all used to having this wording mean that no races are excluded if less than 7 races are scored, but that isn't what the rule says.

"excluding her worst score only after seven (7) races have been completed."

I think that covers the <7 races situation.

I'm probably going down a rat hole here, but defining what happens only after 7 races have been completed does not necessarily define what happens if less than 6 races are completed. A2.1 does not define a series as being the total of all races with no score excluded, it only mentions it as a possibility. We are making the assumption that if the worst score is discarded if 7 races are scored, it means no scores are discarded if only 6 races are sailed. Common sense says this is the correct assumption; I just don't see how the wording of A2.1 supports the assumption.

I'm probably going down a rat hole here, but defining what happens only after 7 races have been completed does not necessarily define what happens if less than 6 races are completed. A2.1 does not define a series as being the total of all races with no score excluded, it only mentions it as a possibility. We are making the assumption that if the worst score is discarded if 7 races are scored, it means no scores are discarded if only 6 races are sailed. Common sense says this is the correct assumption; I just don't see how the wording of A2.1 supports the assumption.

Another way of looking at this: assume the wording in the SIs says a boat's series score is the sum of her scores with her worst race excluded only after 7 races have been sailed. 6 races are sailed, and no scores are excluded. A boat files for redress, claiming her score was made worse by not having her worst score excluded as defined in A2.1 and modified by the SIs. What facts based on the rules lead to the conclusion that no redress should be given?

The three conditions for redress are:

I think we can agree on the first two.  So the RC would have had to made an improper action by drafting a sailing instruction that could be interpreted in more than one way.

The wording of A2.1 says (in part), "that a specified number of scores will be excluded if a specified number of races are completed." Only after 7 races have been completed (notice the terminology - completed, not sailed) seems to satisfy that requirement.

"Only after" is a condition that must be met before excluding a race.  Am I missing something?

I understand that A2.1 is being considered for revision in the next quad.  The default being a competitor's worst score will be excluded, will be removed.  As written now, if the SIs are silent on excluded scores, a boat's worst score shall be excluded.  This is sometimes overlooked by Organizing Authorities and race officials. It is not uncommon to lose one day of a two day regatta.  With three or fewer races, excluded scores can have unexpected and unwanted results.  

In the case again where the SIs are silent and only one race is sailed, it is my opinion that there is no worst score.  I base this upon the dictionary definition "most unfavorable".  I think in order to have a worst of anything, two or more are required.

Unless the results contain DNE scores, it doesn't make a difference to the rank of the boats if there is a discard or no discard when only one race is sailed.  The results will look identical.

Add to the sentence : This changes A2.1

But it doesn't change A2.1 and that sentence is not only not needed but is incorrect.  

As mentioned above there may be a revision to A2.1 in the next quad. My hope is that the words 'excluding her worst score' are dropped from this rule. 'Different arrangements' would then be needed to allow for dropping races from a series score not the other way around.

I am not a fan of dropping races for these reasons:
1. It's busy work for the scorer.
2. It seldom changes rankings.
3. When it does change rankings it rewards inferior performance on the race course.

So why do it?

I believe that racers should be responsible for their performance on the race course, for good and for bad. I like to see competitors continue to try to improve their position and not give up just because they know they might drop the race from their series score.

An idea that I have been floating to implement, in one of the series that I oversee, is to turn this whole idea on its head and drop a competitors best score from the series. Good scores are just as big an anomaly to those at the back of the fleet as bad scores are to those at the top. So why not flip the dropped race scenario? I think it would add new motivation to keep improving as the race progresses.

This high score drop idea does go against my conviction that dropping races is a bad idea, for the same reasons. (The jury is still out as to who gets rewarded by this dropped race.) I continue to advocate for not dropping race scores.

There are arguments both for and against having an excluded score.

In my experience, it's certain dinghy classes (Thistle) and keelboat (T-10) that do not have excluded scores - more out of tradition than anything else.

High-performance boats (skiffs, catamarans) prefer to have an excluded score.  They typically run more, shorter races than other classes.  It's not unusual to have a catastrophic equipment failure in those classes.

And I disagree that it "seldom changes rankings" and that it "rewards inferior performance on the race course."  In the recent Club 420 Nationals in Chicago, the winning team had a 1, 1, 1, 1, 1, UFD, 1 scoreline.  They were clearly the best team.  Without an excluded race, they would have placed 10th.

Jerry re: " This is sometimes overlooked by Organizing Authorities and race officials."

BINGO!!  In the end, it's really an argument around "intension".  What's a more natural and common intension.  In local racing, 3 day regattas are getting converted to 2 .. 2 day regattas to 1.  Except on the championship level, I'd wager that over the past 10 years the average races per regatta has fallen drastically, with 3-4 race single day events becoming more common.

With that change in racing habits, it would seem to make sense to have the default be no-drops and the intentional-change be adding drop(s) based on a number of completed races in the race docs.