| Willian vs King | 69–78 | 46.94% |
| Willian vs Jin | 52–58 | 47.27% |
| Willian vs Bryan | 46–59 | 43.81% |
| Willian vs Kazuya | 45–56 | 44.55% |
| Willian vs Clive | 36–53 | 40.45% |
| Willian vs Asuka | 32–48 | 40.00% |
| Willian vs Reina | 33–45 | 42.31% |
| Willian vs Dragunov | 32–44 | 42.11% |
| Willian vs Law | 33–30 | 52.38% |
| Willian vs Eddy | 21–40 | 34.43% |
| Willian vs Steve | 20–37 | 35.09% |
| Willian vs Alisa | 13–33 | 28.26% |
| Willian vs Lili | 18–27 | 40.00% |
| Willian vs Paul | 22–22 | 50.00% |
| Willian vs Nina | 9–35 | 20.45% |
| Willian vs Jun | 16–27 | 37.21% |
| Willian vs Azucena | 21–20 | 51.22% |
| Willian vs Xiaoyu | 14–25 | 35.90% |
| Willian vs Heihachi | 13–25 | 34.21% |
| Willian vs Devil Jin | 10–26 | 27.78% |
| Willian vs Hwoarang | 13–22 | 37.14% |
| Willian vs Lee | 15–20 | 42.86% |
| Willian vs Victor | 13–22 | 37.14% |
| Willian vs Yoshimitsu | 10–12 | 45.45% |
| Willian vs Lidia | 8–12 | 40.00% |
| Willian vs Leroy | 4–15 | 21.05% |
| Willian vs Feng | 4–14 | 22.22% |
| Willian vs Lars | 8–10 | 44.44% |
| Willian vs Leo | 9–5 | 64.29% |
| Willian vs Zafina | 3–11 | 21.43% |
| Willian vs Kuma | 3–7 | 30.00% |
| Willian vs Jack-8 | 4–5 | 44.44% |
| Willian vs Claudio | 2–7 | 22.22% |
| Willian vs Armor King | 4–5 | 44.44% |
| Willian vs Anna | 0–5 | 0.00% |
| Willian vs Raven | 2–2 | 50.00% |
| Willian vs Miary Zo | 0–4 | 0.00% |
| Willian vs Shaheen | 2–0 | 100.00% |
| Willian vs Fahkumram | 2–0 | 100.00% |
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.