Tom is of course correct, but this got me thinking about 11A and 11B. As I looked at them, the following two thoughts occurred, which I dedicate to Micah. I apologize if I shouldn’t have posted this in this thread - but rather in Running Chess Tournaments.
Both of these rules use the phrase “last ten” moves. While we all know what is meant due to past precedent and the evolution of these rules, we should keep in mind that rules may sometimes confuse new players, and this is even more so if the rule is imprecisely worded - such as this rule is.
What is meant here is the “prior ten moves” or “previous ten moves” - or even more precisely “immediately prior ten moves.” Because the rule references either player’s last ten moves, there is no need to clarify that we don’t wish to consider only 5 full move pairs - the rule is speaking of the moves of only one player or the other.
But by using the word “last,” a newbie could consider this to be a player’s last ten moves of the game - which is, of course, silly - but not for someone inexperienced.
If there is a list of minor clean-ups, this may be one. The first reference should be “immediately prior (“prior”) ten moves” and can just be “prior” thereafter.
Secondly, out of curiosity, is there a reason not to simplify this by moving to the FIDE version of this rule? I understand that the 10 move look back was initially a compromise since the lookback was originally all the way to the beginning of the game. Why do the lookback at all anymore?