Sort Quick — The Corner-First Method
Sort Quick has a known method that solves it in under 90 seconds reliably. The corner-first method, the L-shape trick, and the 3-cycle move explained.
Sort Quick (#14) is the 15-puzzle: a 4×4 frame with fifteen numbered tiles and one empty space, scrambled, and your task is to slide tiles into the empty space until they read 1 through 15 in order. New players solve it by moving "whatever looks easiest next" and almost always get stuck around the third row. There is a much better method, used by people who solve the 15-puzzle in seconds, and it is genuinely learnable in an hour. This guide walks through it.
The single rule the corner-first method follows
Once you have placed two adjacent tiles correctly — say, 1 in the top-left and 2 next to it — you must never move them again. The rest of the puzzle has to be solved without disturbing those tiles. This single constraint is the entire engine of the method: you progressively place tiles, lock them, and reduce the remaining puzzle to a smaller and smaller area.
The reason most players get stuck is that they break this rule without realising it. They solve 1, 2, 3, 4 across the top row, then accidentally need to slide 1 out of position to place 5 — and the row falls apart. The corner-first method exists to prevent exactly this situation.
The order to place tiles in
Solve in this order: row 1 (tiles 1, 2, 3, 4), then column 1 of rows 2-4 (tiles 5, 9, 13), then row 2 (6, 7, 8), then column 1 of rows 3-4 already done, then row 3 (10, 11, 12), then row 4 (13 already done, then 14, 15, with the empty space at the corner).
Each phase reduces the puzzle. After row 1 and column 1 are placed, you have a 3×3 sub-puzzle in the bottom-right. After row 2 is placed, you have a 3×2 sub-puzzle. The final 2×2 is solved with a specific small rotation. The whole game is a sequence of constraint reductions.
The corner-placement trick
The hardest part of the corner-first method is placing the right-edge tile of any row, because you cannot just slide it directly without disturbing the rest of the row. The trick is called the "L-shape": instead of placing tile 4 directly into the top-right corner, you place tile 3 in the corner first, then tile 4 immediately below it (in position where tile 8 will eventually go), and then rotate them into their final positions with a four-move sequence: empty space below 3 → slide 3 right (into corner) → slide 4 up → done.
This sounds confusing until you do it once. There is the same trick for the bottom of each column. Practise the L-shape on row 1; once it feels natural, the rest of the puzzle is identical patterns at smaller scales.
The 3-cycle
The other key move in the 15-puzzle is the 3-cycle: a sequence of moves that rotates three tiles around a fixed point while leaving everything else unchanged. The 3-cycle is what lets you adjust the position of one tile in a partially-solved row without disturbing the placed tiles. Specifically, the move sequence "empty up, left, down, right" performed near a corner produces a 3-cycle that is the engine of the entire method.
You do not need to memorise the move sequence consciously. After about twenty plays, your fingers learn it. What matters is that you trust the method — you commit to the L-shape, you commit to never disturbing placed tiles, and you commit to letting the puzzle shrink in steps.
The plateau
Most players plateau around 90 seconds for a full solve. Getting under 60 seconds requires not the method (you already have it) but execution speed: doing the L-shape without thinking, recognising sub-puzzles instantly, never pausing to read the numbers. That comes from repetition. Twenty solves and you will be at 90 seconds reliably; another fifty and you will be under 60. The 15-puzzle world record is under 4 seconds, set by people who have done the L-shape several million times. You will not get there. You can comfortably reach a minute, which is good enough to feel that you have actually learned something.
Published · 14 May 2026 · Written and signed by Bill