Are there squares right next to a horse that it can never move to directly?
These answers restate the rules implemented by our open-source engine, which follows the WXF laws and is regression-tested against the official 110-diagram repetition casebook. Where an answer refers to a specific position, that position lives on the linked reference page, where the build verifies it against the engine before publishing.
Direct answer
Yes. A horse's move is one point orthogonally and then one point diagonally outward, so the four points immediately beside it, straight up, down, left and right, are never destinations in their own right. Those points are only ever the leg the horse steps through on its way somewhere else, and a piece sitting on one of them blocks two of the horse's eight moves at once rather than being a square the horse could land on.
Why this trips people up
Players arriving from chess expect a knight-shaped piece to threaten everything an actual knight threatens, and to be blocked by nothing. A horse threatens the same eight destination points a knight does, but it also has four permanently unreachable neighbours that matter enormously for calculation, since anything sitting on one of them is doing double duty as a blocker.
Why it matters in defence
Putting a piece directly beside an enemy horse, rather than on one of its actual destination points, is often the cheapest way to blunt it. The piece is in no danger of being captured by that horse next move, since the horse cannot land there, and it simultaneously removes two of the horse's options.
Related questions
Does this apply to all four orthogonal neighbours equally?
Yes, each one blocks exactly two of the horse's eight potential moves, the two that would have stepped through it.
Can the horse ever capture a piece on one of those adjacent points some other way?
No. If it wants that piece it needs a different piece entirely, the horse itself simply cannot reach it.
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