The New Sudoku Players' Forum

[tso]

Condescending comments are out of place on this forum - I'm sure you'll agree.

Yes. I do seem to come off that way. Sorry about that.

Also, rows 3/6/7 make a swordfish.

This was very interesting to me. A solver, if she wanted to, could make the swordfish elimination as her very first move in the puzzle, making EIGHT candidate eliminations, and nothing complex to do for the rest of the solution! Subjectively, swordfish are fun to find. I don't usually use pencil marks until I'm stuck -- but this shows me that if I use pencil marks to start, I might find a pattern that may not be there later. This swordfish would normally be cleared by simpler means.

[Jeff]

Don't forget the xy-chain. Although it is a forcing chain, but it is one of the simplest and has a fixed pattern to follow. No need to do any filtering nor any checking on weak/strong links nor approaching the prey from 2 directions. Simple xy-chain 47-74-47-74 eliminates the 4 in r1c7.