| Siewek vs King | 14–8 | 63.64% |
| Siewek vs Reina | 8–10 | 44.44% |
| Siewek vs Steve | 9–8 | 52.94% |
| Siewek vs Law | 6–9 | 40.00% |
| Siewek vs Jin | 5–9 | 35.71% |
| Siewek vs Kazuya | 1–13 | 7.14% |
| Siewek vs Dragunov | 3–9 | 25.00% |
| Siewek vs Claudio | 3–8 | 27.27% |
| Siewek vs Lili | 4–6 | 40.00% |
| Siewek vs Clive | 4–6 | 40.00% |
| Siewek vs Hwoarang | 3–6 | 33.33% |
| Siewek vs Bryan | 4–4 | 50.00% |
| Siewek vs Nina | 1–7 | 12.50% |
| Siewek vs Yoshimitsu | 3–4 | 42.86% |
| Siewek vs Heihachi | 5–2 | 71.43% |
| Siewek vs Lars | 2–4 | 33.33% |
| Siewek vs Jun | 3–3 | 50.00% |
| Siewek vs Jack-8 | 3–2 | 60.00% |
| Siewek vs Alisa | 0–5 | 0.00% |
| Siewek vs Anna | 3–2 | 60.00% |
| Siewek vs Xiaoyu | 0–4 | 0.00% |
| Siewek vs Asuka | 2–2 | 50.00% |
| Siewek vs Victor | 2–2 | 50.00% |
| Siewek vs Azucena | 2–1 | 66.67% |
| Siewek vs Eddy | 2–1 | 66.67% |
| Siewek vs Paul | 2–0 | 100.00% |
| Siewek vs Feng | 0–2 | 0.00% |
| Siewek vs Shaheen | 0–2 | 0.00% |
| Siewek vs Lee | 2–0 | 100.00% |
| Siewek vs Kuma | 0–2 | 0.00% |
| Siewek vs Zafina | 2–0 | 100.00% |
| Siewek vs Lidia | 0–2 | 0.00% |
| Siewek vs Leroy | 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.