How chess tournament pairings work

A plain-language guide for parents. No math needed. If this is your family’s first tournament, start here.

Try the pairing demo

If my child loses, are they out?

No. Most scholastic tournaments use the Swiss system: every player plays every round, win or lose. A win is worth 1 point, a draw ½ point, and a loss 0. Whoever has the most points at the end wins.

How is the next opponent chosen?

Before each round, players are sorted into score groups: everyone with the same number of points. Inside each group, players are listed by rating, and the top half plays the bottom half.

Example: eight players each have 2 points. Player #1 plays #5, #2 plays #6, #3 plays #7, and #4 plays #8. The strongest players don’t meet too early, and the leaders end up facing each other in the last rounds.

Two players never meet twice in the same tournament, and the program also tries to balance white and black.

Watch a small tournament get paired

Ten made-up players, five rounds. Make the pairings, play the games, and watch what happens when a score group has an odd number of players.

Round 1 of 5

Score groups

0 points10 players

Ana 1450Mateo 1385Sofía 1320Diego 1260Valeria 1200Luis 1140Camila 1075Jorge 1010Isabella 950Daniel 880

Boards

Press “Make pairings” to see who plays whom.

Everyone starts with 0 points, so round 1 is one big score group: the top half plays the bottom half.

Why did my child play someone with a different score?

Because a score group had an odd number of players. One player is left over and gets paired with someone from the group just below. Directors call this floating. Under US Chess rules, the lowest-rated player in the odd group moves down to play the highest-rated player available in the next group.

This is normal and happens every round. We ran 1,000 computer simulations of a 357-player, 8-round tournament:

About half
of the score groups had an odd number of players each round
~27
floats in a typical tournament of that size
93%
of players never had to move up to a higher group

So floating is common across the tournament but rarely lands on the same child more than once. The rules also try hard not to float the same player in back-to-back rounds.

Why did my child have black two games in a row?

The program tries to give everyone white and black about equally and to switch colors when it can. But matching scores comes first: playing someone with the same score matters more than getting the “right” color. The same color twice in a row is allowed. Three in a row is avoided whenever possible.

What is a bye?

If the tournament has an odd number of players, one player has no opponent that round and receives a bye, which usually counts as a win (1 point). It goes to a low-scoring player and never to the same player twice. Many tournaments also let you request a bye in advance if your child has to miss a round; those are usually worth ½ point or 0. Check the event’s rules for the exact values.

How do I know the pairings aren’t being manipulated?

It’s a fair question, and you are allowed to ask it. Here’s what protects every player:

  • Pairings are made by software that follows the published rulebook. With the same results and ratings, anyone can check them.
  • Tournament directors (TDs) are certified by US Chess and can lose that certification for misconduct.
  • Pairings, results, and the full round-by-round wall chart are posted on this site every round, so the whole history of the event is public from your phone.

Two different pairing programs can sometimes produce slightly different pairings that are both correct. The rules also give directors some room to make changes, for example to keep brothers and sisters or teammates from playing each other when the event announces that policy, or to fix a result that was entered wrong.

How to check a pairing yourself

  • Open your child’s line in the wall chart. Is this round’s opponent in the same score group, or the group right next to it?
  • Have these two players already played each other? They shouldn’t have.
  • Is last round’s result posted correctly? A wrong result is the most common real problem, and the easiest one to fix.
  • Has your child had the same color three or more times in a row?

If something looks wrong

Find a tournament director before the round starts, with your child’s name and the round number. Ask calmly: “Can you help me understand this pairing?” Most questions take a minute to answer. If you’re still not satisfied, ask how to make a formal appeal. Please don’t approach other players or their families about pairings.

Words you’ll hear at the tournament

TD (tournament director)
The certified official who runs the event, makes the pairings, and settles disputes.
Pairings
The posted list of who plays whom, on which board, and with which color.
Score group
All players with the same number of points.
Rating
A number that estimates playing strength. It goes up after good results and down after bad ones.
Float
Being paired outside your own score group because that group had an odd number of players.
Bye
A round without an opponent, usually because of an odd number of players or because you asked to skip it.
Wall chart
The full table of every player’s opponents, colors, and results, round by round.
Variation
An official rule option the organizer chose and announced before the event.