Swiss pairings and tiebreaks without the arithmetic.

Chess almost never uses a knockout, because eliminating half the field after one game defeats the purpose of a tournament people entered to play chess in. It almost never uses a full round robin either, past about ten players, because twenty-four entrants playing everyone once is 276 games. The Swiss system exists to solve exactly this: everyone plays every round, and players are paired against others on the same score.

The round count is what determines whether the result is meaningful. As a rule of thumb you need enough rounds that a single undefeated player is mathematically possible to isolate — five rounds separates up to 32 players, six up to 64, seven up to 128. Running four rounds for twenty-four players reliably produces a three-way tie at the top and a tiebreak nobody is happy about.

The other advantage over a bracket is that all boards play simultaneously, so the tournament length depends on the time control and the round count, not on the number of entrants. Twenty-four players or forty-eight, five rounds at G/25+5 is the same afternoon. How the Swiss system works covers the pairing rules in detail.

A Swiss tournament ends with players tied on points far more often than not — that is a property of the format, not a failure of it. Which is why the tiebreak system matters more in chess than in any other sport, and why it has to be published in the entry conditions rather than decided afterwards.

The common systems all measure the same idea from different angles: how strong were the opponents you actually faced. Buchholz sums your opponents’ scores. Median Buchholz drops the highest and lowest before summing, which reduces the distortion from one opponent who withdrew. Sonneborn-Berger weights each opponent’s score by whether you beat or drew them. Direct encounter is simplest of all and only resolves two-way ties.

None of these is calculable in your head, and all of them are calculable instantly from results that are already recorded. The point of running the tournament in software rather than on paper is that the tiebreak is not a separate task at the end of a long day — it is just the standings, already sorted.

The rhythm of a chess tournament is different from a court sport. Every board starts together and finishes at wildly different times — one game is over in twenty minutes, another goes to an endgame and takes the full time control. The next round cannot be paired until every result is in, so the whole room waits on the slowest board, and then waits again while the pairings are worked out.

That second wait is the one worth removing. Pairing twenty-four players by hand takes ten to fifteen minutes per round even for someone experienced, and it happens five times. Over a day that is well over an hour of a full playing hall sitting idle, and it all falls on one person who is also arbitrating.

With the results already recorded as they finish, the next round exists the moment the last game does. Players check the public link for their board and colour instead of crowding the pairing sheet, and the standings — with tiebreaks — are visible throughout rather than announced at the end.