| Seiko vs Reina | 21–22 | 48.84% |
| Seiko vs Kazuya | 13–21 | 38.24% |
| Seiko vs Hwoarang | 15–16 | 48.39% |
| Seiko vs Jin | 13–16 | 44.83% |
| Seiko vs Steve | 16–13 | 55.17% |
| Seiko vs King | 15–12 | 55.56% |
| Seiko vs Armor King | 12–15 | 44.44% |
| Seiko vs Miary Zo | 11–12 | 47.83% |
| Seiko vs Paul | 8–10 | 44.44% |
| Seiko vs Law | 6–9 | 40.00% |
| Seiko vs Yoshimitsu | 10–5 | 66.67% |
| Seiko vs Dragunov | 6–9 | 40.00% |
| Seiko vs Lidia | 6–6 | 50.00% |
| Seiko vs Heihachi | 4–8 | 33.33% |
| Seiko vs Devil Jin | 5–6 | 45.45% |
| Seiko vs Eddy | 5–5 | 50.00% |
| Seiko vs Bryan | 3–6 | 33.33% |
| Seiko vs Lars | 6–3 | 66.67% |
| Seiko vs Jun | 3–6 | 33.33% |
| Seiko vs Jack-8 | 1–7 | 12.50% |
| Seiko vs Lili | 5–3 | 62.50% |
| Seiko vs Asuka | 3–4 | 42.86% |
| Seiko vs Claudio | 2–5 | 28.57% |
| Seiko vs Azucena | 5–2 | 71.43% |
| Seiko vs Alisa | 3–3 | 50.00% |
| Seiko vs Raven | 5–1 | 83.33% |
| Seiko vs Fahkumram | 3–3 | 50.00% |
| Seiko vs Nina | 2–3 | 40.00% |
| Seiko vs Anna | 2–3 | 40.00% |
| Seiko vs Lee | 1–3 | 25.00% |
| Seiko vs Leroy | 3–1 | 75.00% |
| Seiko vs Clive | 1–3 | 25.00% |
| Seiko vs Leo | 2–1 | 66.67% |
| Seiko vs Shaheen | 2–1 | 66.67% |
| Seiko vs Zafina | 0–3 | 0.00% |
| Seiko vs Xiaoyu | 2–0 | 100.00% |
| Seiko vs Feng | 1–1 | 50.00% |
| Seiko vs Victor | 0–2 | 0.00% |
| Seiko vs Kuma | 0–1 | 0.00% |
| Seiko vs Panda | 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.