Aji
Aji is a Go word that literally means taste — the flavor a position leaves behind. A stone you played deep in your opponent’s area might look dead. But if there’s still a chance it could be revived, or used as a threat, or become the seed of a cut, it isn’t worth nothing. It has aji. Your opponent has to keep half an eye on it even though, right now, it does nothing at all.
Aji is potential you haven’t spent. Its whole value is that you haven’t spent it.
The discipline is restraint, and Go has a word for getting it wrong: aji-keshi, “erasing the taste.” It’s the move — usually a premature forcing move — that destroys your own latent possibilities by making the opponent fix the very weakness you were saving. The cleanest example is the proverb don’t peep where you can cut. A peep forces your opponent to connect; once they connect, the cut you might have made later is gone forever. You traded a live option for a single small gain, and you’ll miss it.
There’s a saying among players that there’s a hair’s breadth between a good forcing move and aji-keshi. The two look almost identical for several moves. Telling them apart is most of the skill.
This is optionality made visible on a board. An option is valuable precisely because you don’t have to exercise it yet; exercise it early and you throw away the time value. Keeping cards face-down, a route untaken, a relationship warm but uncalled — these are aji. The reserve is the asset, and the moment you reach for it, it stops being one.
It cuts the other way too. You can erase your opponent’s aji — play the move that quietly removes their lingering tricks and settles a region on your terms. It often looks wasted because it captures nothing. What it captures is the future: it turns an ambiguous corner into one where they have no more options. Sometimes the strongest move on the board does nothing but kill the other side’s possibilities.
The warning is that aji is not a plan. Potential that never becomes anything is just an excuse to avoid committing, and there’s a real failure mode of keeping every option open forever while the game decides itself somewhere you weren’t looking. Aji has a shelf life. Left too long, the position hardens around it and the taste goes flat.
So hold the possibility, but don’t fall in love with holding it. The art — and Go players spend years on this single judgment — is sensing the one moment the taste is richest, and spending it then.
Go Deeper
Books
- Beyond Forcing Moves by Shoichi Takagi — Directly on the line between a good forcing move and aji-keshi: when to spend latent potential and when to wait.
- Attack and Defense by Akira Ishida and James Davies — Treats aji as a central theme in pressuring weak groups.
Online
- Sensei’s Library (senseis.xmp.net) — The long-running Go wiki has careful, diagrammed pages on aji, aji-keshi, and kikashi.