Go tournament time controls
Most Go tournaments run on byo-yomi — commonly 45 to 60 minutes of main time plus five 30-second periods in Europe. American Go Association events use Fischer bonus time instead, with the US Open at 60 minutes + 20 seconds per move. Events under Ing rules use Ing overtime, where a player may buy up to three extra periods at two penalty points each. Professional games run to hours of main time.
European tournaments
European events, run under the European Go Federation's tournament rules and its member federations, mostly use byo-yomi. The main time varies with the schedule; the overtime almost always looks the same.
| Setting | Round length | Typical event |
|---|---|---|
| 45 min + 5 × 30 s | ~2 h | Weekend tournaments, three rounds a day |
| 60 min + 5 × 30 s | ~2.5 h | Larger events, two rounds a day |
| 30 min + 5 × 30 s | ~1.5 h | Fast weekend events, four rounds a day |
| 10 min + 3 × 30 s | ~30 min | Side events, blitz tournaments |
Five periods of 30 seconds is close to a European constant: enough to finish a long endgame without letting a round overrun. The main time is the scheduling dial.
The EGF rules also cover Ing overtime, in which a player whose main time expires may take up to three periods of one sixth of the main time, each costing two points at scoring. It is unusual, but if your event uses it, the clock has to count both the periods and the penalty. See Ing, NHK and Progressive.
American tournaments
The AGA runs on bonus time, not byo-yomi. The US Open is played at 60 minutes + 20 seconds per move, and the AGA publishes minimum settings for a game to count for rating:
| Setting | Character |
|---|---|
| 60 min + 20 s | US Open format |
| 30 min + 10 s | Shortest rated minimum; brisk |
| 20 min + 15 s | Middle ground |
| 10 min + 20 s | Little main time, generous bonus |
The scheduling argument is the reason. Under byo-yomi a game can in principle continue indefinitely, since every move in time resets the period; under bonus time the clock still trends downward, so rounds finish nearer their planned length. Many American clubs also still use Canadian overtime — 45 minutes plus 25 stones per 10 minutes — which works on simple equipment and is easy to explain.
Professional and title games
Professional Go uses byo-yomi with long main times. A regular professional game commonly gives each player two to three hours plus five 60-second periods. Major title matches go considerably further — the longest Japanese titles are played over two days with main times measured in many hours, the game sealed overnight and resumed the next morning.
Japan's televised NHK tournament is the deliberate opposite: no main time at all, 30 seconds per move, plus ten one-minute reserve periods. It exists to fit a broadcast slot while keeping the play serious, and it produces a distinctive steady rhythm.
Choosing a control for your own event
Work backwards from the schedule, because the schedule is the constraint that cannot flex:
- Decide rounds per day and the length of the day. Four rounds in eight hours leaves under two hours per round including pairing, breaks and overruns.
- Budget about 75% of that for play. A two-hour slot means a control that finishes in about 90 minutes.
- Two players each using their main time plus overtime is roughly 2.5 × the main time. A 30-minute main time makes a 75-to-90-minute game. That is where 45 min + 5 × 30 s for a two-hour round comes from.
- Then pick the overtime. Five periods of 30 seconds is the safe European default. If you need harder guarantees on finishing time, use bonus time as the AGA does.
- Say the control in the announcement, exactly. "45 min + 5 × 30 s byo-yomi" is unambiguous. "45 minutes" is not, and will be interpreted three different ways.
Running an event on phones
Phones as tournament clocks are increasingly normal at club level, and the practical requirements are specific. Every board needs the same control, set correctly, and the director needs to be able to fix mistakes without restarting games.
Byoyomi Timer covers this: presets for the standard tournament settings, custom controls that can be named and saved so the same setting is reproducible across boards, and referee tools that adjust time, periods and stones mid-game. The screen stays awake, the clock keeps running on the Lock Screen through a Live Activity, and it works with no connection — useful in venues where signal is poor.
Two things to tell players in the briefing: silence notifications, and decide as a venue whether the spoken countdown is on. Fifteen boards each counting down aloud is not a good room to think in — the beep-only and silent modes exist for exactly this.
Turn your iPhone into a real Go clock
Byoyomi Timer plays every Go time system — byo-yomi, Canadian overtime, Fischer bonus time, Ing — and reads the seconds aloud like a human timekeeper.
Coming soon to the App Store