Komi in Go: Why White Gets Bonus Points for Going Second
⏱ Read ~5 min · Updated July 2026 · Part of: Learn Go
In Go, Black moves first — on an empty board, that's a real advantage. Komi is the remedy: White gets bonus points upfront to balance it.
| English | 中文 | Plain meaning |
|---|---|---|
| komi | 貼目 | White's compensation points |
| first-move advantage | 先手優勢 | Black's edge from moving first |
| half-point | 半目 | prevents draws |
| scoring | 計分 | determining the winner |
1. Why komi exists
Without komi, Black's first-move advantage makes the game unfair — when players are evenly matched, Black tends to win (because moving first = grabbing the good points first). Komi removes this edge: before the game even starts, White is awarded some points.
⚖️ It's a built-in "fairness patch" — like how White has a tiny edge in chess, but Go compensates with bonus points rather than other mechanisms.
2. The history of komi
Komi wasn't always there — it was added gradually:
- Early (early 20th century): no komi, Black was clearly advantaged. Professional players noticed the unfairness.
- Experimentation: started at 4.5, then 5.5. Found insufficient (Black still advantaged).
- Modern: Japan/Korea settled on 6.5, China on 7.5. These numbers were tuned from tens of thousands of professional game statistics — the goal is "with perfect play, the result narrowly favors White."
📊 Why keep adjusting? Because pro statistics show that at a given komi, Black/White win rates skew → adjust the number → re-statistics → until close to 50/50.
3. Komi differences across rules
| Ruleset | Komi | Notes |
|---|---|---|
| Japan/Korea | 6.5 | most common |
| China | 7.5 | Chinese rules use area scoring, higher komi |
| Ing Cup | 7.5 | Ing rules, komi + special scoring |
| Historical | 4.5-5.5 | obsolete |
Different rulesets use different komi because their scoring methods differ (territory vs area scoring). But the goal is the same: balance first-move advantage.
4. The half-point — preventing draws
Notice the .5? This half-point guarantees no draws — every game is decided by at least half a point.
- Without the half (e.g., komi of 6 whole points) → both sides' scores can be exactly equal → draw (jigo).
- With the half (e.g., 6.5) → the total always has a decimal → can never be equal → there's always a winner.
Why avoid draws? Tournaments need a winner (knockout can't draw). The half-point is an elegant rules design.
5. Komi on small boards
On 4×4 capture puzzles, komi is irrelevant — there's no territory to count, the game is decided by captures. Komi only matters in territory-scoring games on 9×9 or larger. brainGO's 4×4 puzzles don't use komi at all; it's a concept you'll meet when you move to full Go.
6. The 3 most common komi questions from beginners
- "Does komi affect me?" Beginners don't need to calculate komi — just know White has some compensation. It's added automatically when scoring.
- "Why 6.5 and not a whole number?" The half-point prevents draws (see section 4).
- "Does mahjong have komi?" No. Komi is unique to Go (because the first-move advantage is large). Other games balance differently.
How to train it
Komi is for later — start with captures first.
FAQ
What is komi and why does White get bonus points?
Because Black moves first (first-move advantage — grabbing good points first). Without compensation, Black is clearly advantaged. Komi = awarding White some points before the game starts, to balance first-move.
Why does komi have a half-point (.5)?
The half-point guarantees no draws — the total always has a decimal, so both sides can never be equal. Tournaments need a winner; the half-point ensures one.
Why do different rulesets have different komi?
Because their scoring methods differ (Japan/Korea territory scoring 6.5, Chinese area scoring 7.5). Under different scoring, the compensation needed to balance first-move also differs. But the goal is the same: make Black/White win rates close to 50/50.
Does the 4×4 board need komi?
No. 4×4 capture puzzles are decided by captures, no territory to count. Komi only applies in territory-scoring games (9×9+).
Does the one-point difference between komi 6.5 and 7.5 actually affect the outcome?
Yes — and at the professional level it matters enormously. One point in Go is the smallest scoring unit — on a large board roughly the value of one intersection. Pro games often end with a margin of half a point to one point, and there komi being 6.5 or 7.5 directly decides the winner. Example: a game where Black has 50 points and White has 44 — under Japanese/Korean komi 6.5, White's total is 50.5 and White wins by half a point; switch to Chinese komi 7.5 and White's total is 51.5, winning by one and a half. Same game, different ruleset, immediately different result. This is why rulesets stubbornly keep their own komi — because it drives whole-game strategy (e.g., under Chinese rules White is more willing to grab solid territory).
Was komi reconsidered after AlphaGo?
Yes — and the debate has been intense. AlphaGo and successor AIs (Leela Zero, KataGo) can give precise win-rate estimates — e.g., under a given komi, Black's win rate with perfect play is 52% or 48%. The AI consensus is roughly: 7.5 slightly favors Black (Chinese area scoring has details like "group tax"), while 6.5 is closer to balanced but slightly favors White. This sparked discussion of adjusting to 7 points or a more precise number, but mainstream tournaments still keep the traditional numbers — because changing komi invalidates the statistical basis of all historical pro games, and pros would need to re-adapt. For beginners these differences don't matter, but at the pro level every point of komi is real money.
Related guides
- Learn Go: the visual beginner's guide — the beginner hub (this article's home)
- Go scoring — where komi is added
- Sente and gote — the first-move advantage komi compensates
- Glossary — jigo (draw), komi, etc.
- Board sizes — 4×4 vs 9×9 vs 19×19