Matching Failures

Troubleshooting guide

This guide helps you resolve common issues when Derby cannot generate a complete match schedule.

Why Are Some Teams Not Being Matched?

The matching algorithm pairs entries based on weight within a tolerance window. If teams aren't being matched, it's usually due to one of these reasons:

1. Weight Tolerance Too Tight

If your weight tolerance is too small relative to your weight range, some entries may have no valid opponents.

Solution:

1. Go to Tournament > Settings
2. Increase the Weight Tolerance (try 60-80g)
3. Regenerate the schedule

2. Isolated Cards (Outliers)

If a card's weight is far from others, it may have no valid opponents within tolerance.

How to identify:

• Derby shows a warning icon next to cards with zero pairing options
• Check the Teams tab for cards marked as "optionless"

Solutions:

• Exclude the isolated card using Omit
• Mark it as a Wildcard (reserve entry)
• Increase tolerance to include it

3. Odd Number of Cards

If you have an odd number of active cards, one card cannot be paired.

Solutions:

• Add one more card to make it even
• Exclude (omit) one card
• The algorithm will show which card has a "bye"

4. Same-Owner Constraint

Cards from teams owned by the same player cannot fight each other. If a player owns multiple teams, this reduces pairing options.

Solution: Ensure players don't own too many teams relative to the total teams in the tournament.

5. Teams Have Different Entry Counts

Strict matching expects each active team to have enough registered entries for the phase. If some teams are missing weights, have omitted entries, or are partially registered, they may be excluded from strict matching.

Solution: Enable Flexible Entries in the phase settings. Derby will use the available entries for each team with the selected matching mode and continue matching the rest of the tournament.

Schedule Quality Issues

High Weight Differences

If generated schedules have high average weight differences:

• Try regenerating multiple times (click Generate again)
• Select a different schedule from the generated options
• Check that your cards' weights are properly distributed

Teams Fighting Twice

If Unique Matchups is enabled but teams are still fighting twice:

• You may have too few teams for the number of rounds
• Try reducing the number of rounds
• Add more teams to the tournament

Error Messages

Still Having Issues?

If you continue to experience matching problems:

1. Check the FAQ for additional answers
2. Contact support with your tournament file