Steve: I do agree, in principle, about efficiency. I still have this grey zone when its comes to when I should markup. David refers to the Drudge. Marking up a puzzle is 'character building'. Sometimes I lose patience with a puzzle that appears to be elementary but the puzzle will not fall. Then, when I mark it up, I see that I missed a Naked Triple and I am a bit humbled. So, setting completely unnecessary constraints is part of the fun. Occasionally, for me, an aspect of a puzzle is seen that might be missed if a more structured [efficient?] approach had been applied.
Leren: Your JExocet list is soon going to occupy a considerable amount of my Sudoku time. Using David's Compendium, I now have a grasp of the pattern. Next, I will test myself with puzzles in your list. Then, I will enter the challenge of attacking puzzles that 'might' contain JExocet. Then, it is about adding the pattern to my lexicon. Maybe, at some future time, there will be the joy of identifying a JExocet without any 'help' at all. [well down the road for me]
David: Your compendium currently dominates my Sudoku time. It will be interesting to see puzzles with a late(r) arrival of a JExocet.
enxio27: Thanks for the link. Please do repost the others to keep them in action. Up until quite recently, I saw XY-Chains as too daunting. I first saw the alternate logic to place the XY-Wing as the simplest [shortest] XY-Chain. Then, I used the preferences in Hodoku to create puzzles with short XY-Chains [go to Steps and change the chain length from the default]. I practiced these short ones for a while. Then, I read:https://sysudoku.com/2011/12/06/xy-web/
I have not been to incorporate 'XY Railroads' into my approach, but this post did enable me to see the chain's length as just a descriptor and not a obstacle.