Techniques

These are the steps the solver on this site actually uses, easiest first. Each one has a board taken from a real solve, not a diagram drawn by hand. The level named on the row is where that step first becomes necessary.

The New York Times labels overlap in a way these levels don't. That measurement is written up in why Medium sometimes feels harder than Hard.

  1. Naked single Easy. All 495 NYT Easy puzzles in the archive are 38 clues and never need anything beyond singles.
  2. Hidden single Easy. NYT Easy is singles only. Three of the 495 Easy puzzles place a line hidden single if lines are scanned before boxes, and those three still solve with box hidden singles alone.
  3. Pointing Not Easy. Every one of the 494 NYT Medium puzzles needs pointing or claiming, and none of them needs a pair. About 24% of NYT Hard never goes past pointing either.
  4. Claiming Not Easy. NYT Medium always needs pointing or claiming. The archive doesn't separate the two; both are the locked-candidate step that Medium never skips.
  5. Naked pair Hard. A naked pair is the hardest step on 51% of the 494 NYT Hard puzzles. Nothing in the archive goes beyond triples.
  6. Hidden pair Hard. A hidden pair is the hardest step on 18% of NYT Hard.
  7. Naked triple Hard. Triples, naked or hidden, are the hardest step on 6% of NYT Hard. The archive never needs a harder idea than that.
  8. Hidden triple Hard. Triples of either kind are the hardest step on 6% of NYT Hard. No archived NYT puzzle needs a quad, a fish, or a chain.
  9. Quads Expert. Across all 1,483 NYT puzzles in the archive, the solver never needs a quad. Hard stops at triples.
  10. X-wing Expert. The 1,483 archived NYT puzzles never need an X-wing. Their hardest steps stop at triples.
  11. Swordfish Expert. No puzzle in the NYT archive needs a swordfish. Expert is where this site asks for fish at all.
  12. XY-wing Expert. XY-wings do not appear in the 1,483 NYT puzzles. That set never goes beyond triples.
  13. Simple coloring Mental. Coloring is beyond the NYT archive. None of the 1,483 puzzles needs a chain.
  14. XY-chain Mental. The NYT archive never needs an XY-chain. Medium stops at pointing, and Hard stops at triples.