How Middle tile works

Middle tile fills a one-tile gap between matching animals with their opposite. It follows from Three's a crowd, one of Pawmoku's two rules. In the first 45 library puzzles it decides 300 tiles, in 45 of the boards. Its earliest use there is step 2 of 6x6 puzzle 1.

Why it works

Before: cat, empty, cat, empty, empty, empty.

After: cat, dog, cat, empty, empty, empty.

A cat in the gap would join the two cats into three in a row. A dog separates them.

When to look for it

Look for one empty tile between matching animals, across and down.

Three line examples

Example 1

Before: empty, cat, empty, cat, empty, empty.

After: empty, cat, dog, cat, empty, empty.

Example 2

Before: dog, empty, dog, cat, empty, empty.

After: dog, cat, dog, cat, empty, empty.

Example 3

Before: empty, empty, dog, empty, dog, empty, empty, empty.

After: empty, empty, dog, cat, dog, empty, empty, empty.

Find it in practice

4x4 Puzzle 1: Middle tile first decides a tile at step 6.
6x6 Puzzle 1: Middle tile first decides a tile at step 2.
8x8 Puzzle 1: Middle tile first decides a tile at step 10.