Which Sudoku Techniques Do You Actually Need? 60,000 Puzzles Counted

We counted every technique our hint engine used on 60,000 puzzles: four basics do most of the work, the X-Wing is rarer than you think, and six never came up.

Updated 2026-11-05

How we counted

Our app's hint engine solved each of the 60,000 puzzles in its bank the way a careful person would: at every step it takes the easiest technique that places a digit or rules one out. For each technique we counted in how many puzzles it was used at least once, and in how many it was the hardest step. Which technique the engine meets depends on the order it tries them in, so this is the picture for a solver who always tries the easiest step first.

Every technique, most used first

Used in: the share of all 60,000 puzzles in which the technique was used at least once. Hardest step: the share in which it was the hardest technique the puzzle needed.

Technique	Used in	Hardest step
Last Remaining Cell	100.0%	0.0%
Nearly Complete	100.0%	15.9%
Hidden Single	83.3%	16.7%
Naked Single	82.8%	0.8%
Pointing Pair	24.0%	9.9%
Skyscraper	14.2%	10.1%
ALS-XZ	13.5%	13.5%
XY-Chain	12.4%	9.5%
Naked Pair	10.5%	3.0%
Y-Wing	10.3%	5.6%
W-Wing	6.7%	4.5%
Box/Line Reduction	5.5%	2.2%
Hidden Pair	4.9%	1.0%
Unique Rectangle	2.7%	1.9%
X-Wing	2.2%	0.7%
Empty Rectangle	1.8%	1.1%
X-Chain	1.5%	1.0%
Simple Coloring	1.4%	0.8%
XYZ-Wing	1.4%	0.8%
Pointing Triple	1.1%	0.4%
Naked Triple	0.8%	0.1%
Swordfish	0.3%	0.1%
Finned X-Wing	0.2%	0.2%
Grouped Two-String Kite	0.2%	0.1%
Hidden Triple	0.2%	< 0.1%
Two-String Kite	0.1%	0.1%
Finned Swordfish	0.1%	0.1%
WXYZ-Wing	< 0.1%	< 0.1%
Naked Quad	< 0.1%	< 0.1%
ALS-XY-Wing	< 0.1%	< 0.1%
Hidden Quad	< 0.1%	0.0%

What it means for learning

The four singles are the whole game on Easy and Medium, and they do most of the work everywhere else. The first technique that works on notes is the one to learn next: the pointing pair is used in 24.0% of all puzzles. After it, the Skyscraper, ALS-XZ, the XY-Chain, the naked pair and the Y-Wing each turn up in at least one puzzle in ten.

Stuck on a Hard or Expert Sudoku? The Technique You Need Next →

Famous but rare

The X-Wing is in almost every list of Sudoku techniques, but our engine needed it in only 2.2% of the puzzles, and the Swordfish in 0.3%. Six techniques the engine knows never came up at all: the Jellyfish, Remote Pairs, BUG+1, Sue de Coq, 3D Medusa and the forcing chain. They are worth knowing for the hardest puzzles, but you can solve every puzzle in our bank without them.

Practice

Every Find the Mistake puzzle on this site has exactly one wrong digit, and you can play each board right on its page.

Play the puzzles →