Trust
How a result is made.
Players accept a result when there's a record behind it and rules anyone can read. This page lists what decides a game, a round and a place in the standings on Ocheso, and what we don't do yet.
The referee.
Every move goes to Ocheso's servers. The referee rebuilds the game from its whole record and checks the move against it, so a damaged stored position is caught rather than played on, and repetition is judged on the full history. Chess moves travel as UCI (e2e4, e7e8q); checkers moves as numbered paths (32-28, 28x19x10).
The clock.
Both clocks run on server time; increments are added on the server. When a player's time runs out, the opponent can claim the game. In chess, if the player with time left could never mate, it's a draw. In checkers, running out of time loses.
How a game ends.
Chess
- Checkmate
- Stalemate
- Insufficient material
- Repetition
- The fifty-move rule
- Resignation
- An agreed draw
- The clock
Repetition and the fifty-move rule end the game at once, with no claim needed.
Checkers
- No legal move
- Threefold repetition
- 25 moves each with only kings and no capture
- Resignation
- An agreed draw
- The clock
International (10×10) and Brazilian (8×8), under FMJD rules.
The record.
Every move is stored in order with the game. When something happens off the board, an arbiter can set or correct the result. A correction changes the standings, never a rating.
Pairing rules.
Swiss, in priority order
- No rematches, unless there is no other way to pair the round.
- No impossible colours: after two games in a row with one colour, or two more with one colour than the other, a player gets the other.
- Close scores: players meet their own score wherever possible, and a gap of a full point counts four times as much as half a point.
- Colour preferences, where the rules above allow.
- Top half against bottom half inside a score group, so the leaders meet late.
Every possible pairing is weighed at once and the best set is chosen, so a round that can be paired always is. It follows the Dutch system's priorities; it isn't a certified FIDE pairing program.
With an odd number of players, the lowest-placed player who hasn't had a bye sits out and scores a full point.
- Round robin
- Everyone plays everyone, on Berger tables.
- Knockout
- A seeded bracket. A drawn match goes to a tie-break game, colours reversed, until someone wins.
- Arena
- No rounds. A win is 2 points and a draw 1; two wins in a row start a streak that doubles every result until it breaks.
Tie-breaks.
When players finish level, Ocheso applies the tie-breaks the organiser chose, in the organiser's order. If players are still level after all of them, rating decides.
| Tie-break | What it adds up |
|---|---|
| Buchholz | The final scores of everyone you played |
| Buchholz Cut-1 | The same, leaving out your lowest-scoring opponent |
| Sonneborn-Berger | Each opponent's final score, times what you scored against them: all of it for a win, half for a draw |
| Direct encounter | The points you scored against the other players on your score |
| Wins | Games you won |
| Progressive | Your running score after each round, added up, so early wins count for more |
Buchholz
- What it adds up
- The final scores of everyone you played
Buchholz Cut-1
- What it adds up
- The same, leaving out your lowest-scoring opponent
Sonneborn-Berger
- What it adds up
- Each opponent's final score, times what you scored against them: all of it for a win, half for a draw
Direct encounter
- What it adds up
- The points you scored against the other players on your score
Wins
- What it adds up
- Games you won
Progressive
- What it adds up
- Your running score after each round, added up, so early wins count for more
Ratings.
Ocheso uses Elo, with chess and checkers rated separately. K depends on each player's own rating before the game.
| Rating before the game | K |
|---|---|
| Below 2100 | 32 |
| 2100 to 2399 | 24 |
| 2400 and above | 16 |
- A game is rated only when both players moved and the board decided the result: a no-show or a first-move resignation isn't rated.
- An arbiter's result isn't a game, so it isn't rated, and correcting a result doesn't re-rate it.
- Events that organisations run through Ocheso for Platforms, in early access, are unrated unless the organiser chooses otherwise.
- Ratings stay between 100 and 3500.
Who can see what.
- An event can be listed for everyone or left unlisted, for people with the link.
- Organisers can hide the player list.
- Organisers decide whether games can be watched.
- An entry code is visible to the event's organisers only. It's checked inside the database when someone joins, and never returned on the public page.
- An invite link can be rotated, so an old link stops working.
- Co-admins and moderators can see the full player list and decide entries; only the owner and co-admins can set a result.
Security.
Our API holds no service-role key and refuses to start if it's given one. Every request runs as its caller, and row-level security in the database decides what it may read or change. API keys are stored as SHA-256 hashes and shown once. Requests between our own systems are signed with HMAC. Automated tests connect as different people and check what each may do before anything ships.
Where it runs.
- API
- Vercel, Dublin (dub1)
- Database
- Supabase, eu-west-1 (Ireland)
The engines behind Ocheso Agents ship with the API; nothing is downloaded while a request waits.
Not yet.
What Ocheso doesn't do yet
- Screen games for engine assistance.
- Certified FIDE pairings, or FIDE rating.
- PGN or TRF export.
- Payments of any kind.
- Third-party security certification.
When any of these arrives, it'll be on this page and in the changelog.
Questions about a result?
Write to us with the tournament link and the round.