| Kostov vs Jin | 13–11 | 54.17% |
| Kostov vs Law | 4–18 | 18.18% |
| Kostov vs Jun | 12–10 | 54.55% |
| Kostov vs King | 15–5 | 75.00% |
| Kostov vs Eddy | 10–9 | 52.63% |
| Kostov vs Yoshimitsu | 7–11 | 38.89% |
| Kostov vs Hwoarang | 8–8 | 50.00% |
| Kostov vs Reina | 13–3 | 81.25% |
| Kostov vs Steve | 9–4 | 69.23% |
| Kostov vs Nina | 3–9 | 25.00% |
| Kostov vs Feng | 8–2 | 80.00% |
| Kostov vs Dragunov | 1–8 | 11.11% |
| Kostov vs Paul | 6–2 | 75.00% |
| Kostov vs Bryan | 7–1 | 87.50% |
| Kostov vs Kazuya | 4–4 | 50.00% |
| Kostov vs Lili | 2–6 | 25.00% |
| Kostov vs Asuka | 3–4 | 42.86% |
| Kostov vs Lars | 5–2 | 71.43% |
| Kostov vs Devil Jin | 0–6 | 0.00% |
| Kostov vs Victor | 2–3 | 40.00% |
| Kostov vs Leo | 1–3 | 25.00% |
| Kostov vs Panda | 4–0 | 100.00% |
| Kostov vs Heihachi | 2–2 | 50.00% |
| Kostov vs Xiaoyu | 1–2 | 33.33% |
| Kostov vs Lee | 1–2 | 33.33% |
| Kostov vs Raven | 1–2 | 33.33% |
| Kostov vs Alisa | 2–0 | 100.00% |
| Kostov vs Kuma | 0–2 | 0.00% |
| Kostov vs Fahkumram | 2–0 | 100.00% |
| Kostov vs Jack-8 | 1–0 | 100.00% |
| Kostov vs Azucena | 1–0 | 100.00% |
| Kostov vs Clive | 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.