Pairing Logic
The Pairing Logic dialog shows a visual explanation of how SwissSys arrived at the final pairings. It is most useful for answering player questions such as “Why wasn’t I switched with so-and-so?”
Menu path: Pairings → Pairing logic
Understanding the Display
The display resembles pairing cards laid out on a table:
- Players on the left are from the top half of their score group
- Players on the right are their natural opponents from the bottom half
- Color of a player’s piece is not shown here — position in the diagram has nothing to do with color assignment
- Score group breaks are underlined
“Natural pairings” means the expected pairings after any legally-required switches (such as avoiding rematches) but before color-optimization switches.
Lines connect each player to their final opponent. If a player is connected to their natural opponent, no switch was made. If the line goes elsewhere, the color of the line explains why the switch was made.
Line Color Codes
| Reason | Description |
|---|---|
| Avoiding consecutive colors | Required to prevent a player from getting the same color three times in a row |
| Eliminating bad color equalization | The natural opponent was due the same color for equalization |
| Eliminating bad color alternation | The natural opponent was due the same color for alternation |
| Side effect with minimum consequences | Finding the best available match after another player was switched — closest in score and rating, with the best color |
| Improving oddman/float for color or rating | A better oddman was found — either to improve colors or to avoid using an unrated player as the floater |
| Avoiding rematch, other illegal matchup | Required to avoid a pairing that is outright illegal under the rules |
| Better float for color or repeat float | A better player was found to float to the next score group |
A legend at the top of the dialog lists all active color codes.
Color Due Indicators
Players may show a color indicator next to their name:
- W = Strongly due white (equalization)
- WW = Due white to avoid three consecutive same-color games (or other severe imbalance)
- B / BB = Same for black
USCF vs. FIDE
The dialog works slightly differently depending on whether USCF or FIDE pairing rules are in effect. The general structure is the same, but the priority rules for switches differ.
Problem Summary
For a statistical summary of pairing difficulties encountered — such as how many restrictions were hit or how many score groups had problems — click the Problem summary button at the bottom of the dialog.