| Willyam vs Jin | 6–11 | 35.29% |
| Willyam vs Steve | 11–4 | 73.33% |
| Willyam vs King | 5–6 | 45.45% |
| Willyam vs Reina | 8–2 | 80.00% |
| Willyam vs Armor King | 3–5 | 37.50% |
| Willyam vs Eddy | 2–4 | 33.33% |
| Willyam vs Bryan | 2–2 | 50.00% |
| Willyam vs Jack-8 | 0–4 | 0.00% |
| Willyam vs Dragunov | 2–2 | 50.00% |
| Willyam vs Victor | 2–2 | 50.00% |
| Willyam vs Feng | 1–2 | 33.33% |
| Willyam vs Lili | 1–2 | 33.33% |
| Willyam vs Panda | 1–2 | 33.33% |
| Willyam vs Zafina | 1–2 | 33.33% |
| Willyam vs Leroy | 2–1 | 66.67% |
| Willyam vs Azucena | 1–2 | 33.33% |
| Willyam vs Yoshimitsu | 0–2 | 0.00% |
| Willyam vs Hwoarang | 0–2 | 0.00% |
| Willyam vs Devil Jin | 0–2 | 0.00% |
| Willyam vs Lars | 2–0 | 100.00% |
| Willyam vs Claudio | 0–2 | 0.00% |
| Willyam vs Nina | 0–2 | 0.00% |
| Willyam vs Lidia | 2–0 | 100.00% |
| Willyam vs Paul | 0–1 | 0.00% |
Limitations
This data is often requested to give insight into which characters you have more trouble with than others, but it is not particularly helpful for that. The main issue is that it is heavily skewed by how strong the opponents you play are.
For example, this data suggests my worst matchup is clearly vs Reina, but that's just because most of those games are vs Yagami.
There is a way to account for this being worked on. The central idea is to assign each matchup a rating vs you which adjusts based on the result, much like the regular rating but also based on the rating of each player. With this, it would give a better summary of how well you perform vs each character.
In the meantime, this page is here to present the data as requested.