Go One-Stone Variations: How ±1 Stone Flips the Answer

This is a brainGO original. For every position we compute the result of adding or removing each stone, laid out beside the base position — so you can see at a glance which stone flips the outcome and which barely matters. Nobody else offers this.

It does not train "find the best move" (that is tsumego's job) — it trains seeing which stone is the key stone that decides the result. The stone you thought mattered may do nothing; the one you overlooked may be decisive. What carries over is not 4×4 shapes, but the habit of asking "which stone is the key stone?" before you play.

For the full explainer, see why one-stone variations train your Go intuition.