$ cat cards/william-gallas-91-2010/faq/completion-faq-26.md
What happens to the checklist completion percentage if I trade away a card?
card: William Gallas 91 (2010) · category: completion
[Concise Summary]
Trading away your only copy of a card will decrement your collection count and reduce your overall completion percentage.
[Structured Data Grid]
| Inventory Threshold | ≥1 copy required |
| Percentage Impact | -0.15% per card lost |
| Checklist Status Flag | Dynamic state check |
| Recommendation | Only trade duplicates |
Detailed Investigation & Analysis
The companion tracker calculates completion based on active inventory status. If your inventory falls below 1 copy for code 91, the slot is flagged as uncompleted. Keep a duplicate swap buffer to avoid progress regression.
Additional notes for collectors: Ensure checklist entries are verified before confirming trades. Standard trade ratios are calculated relative to card popularity.
[Album Context Specs]
| Card Code | 91 |
| Official Name | William Gallas 91 (2010) |
| Estimated Value | $1.25 USD |
| Album Section | France (2010) |
| Completion Mode | Required Checklist Item |