Hard technique · Technique Academy

Hidden Triple

A hidden triple is three digits that, within one unit, can only go in the same three cells. Those cells may hold other candidates, which are red herrings.

Professor Cryptic, the owl who teaches in the app
Professor Cryptic is thinking

The reasoning

Why does the Hidden Triple work?

Since the three digits must fill the three cells, everything else in those cells can go. Often the triple was hiding behind a crowd of notes.

A worked example

What does the Hidden Triple look like on a real board?

Hidden Triple worked exampleA sudoku board with pencil marks. The Hidden Triple uses R4C4, R4C6, R6C6 and digits 4, 5, 7 (box 5). The move strikes candidates 4 in R4C6, 5 in R4C6, 7 in R4C6, 4 in R6C6, 5 in R6C6.51681834734291216941679825316329156478648584734578192713892681691893854891348913582191458938672389386816918974515437237968398976543892912139
The move strikes candidates 4 in R4C6, 5 in R4C6, 7 in R4C6, 4 in R6C6, 5 in R6C6. Digits 4, 5, 7, box 5.
  • Cells that form the pattern
  • Cells that lose a candidate
  • Struck digit: ruled out

Make it stick

How can you practise the Hidden Triple?

The Technique Academy in Cryptic gives every technique its own lesson and 5 practice boards that need exactly this move.

Get it onGoogle PlayPlay Cryptic on the web

Further reading: HoDoKu's page on this family of techniques.

EasierXY-WingHarderNaked Quad