| Kostfek vs Law | 37–41 | 47.44% |
| Kostfek vs Kazuya | 17–44 | 27.87% |
| Kostfek vs Jin | 23–37 | 38.33% |
| Kostfek vs King | 17–26 | 39.53% |
| Kostfek vs Lili | 18–25 | 41.86% |
| Kostfek vs Anna | 19–19 | 50.00% |
| Kostfek vs Paul | 13–24 | 35.14% |
| Kostfek vs Hwoarang | 21–16 | 56.76% |
| Kostfek vs Steve | 16–21 | 43.24% |
| Kostfek vs Eddy | 12–23 | 34.29% |
| Kostfek vs Clive | 13–22 | 37.14% |
| Kostfek vs Nina | 20–12–1 | 62.50% |
| Kostfek vs Azucena | 9–21 | 30.00% |
| Kostfek vs Heihachi | 10–20 | 33.33% |
| Kostfek vs Jun | 10–18 | 35.71% |
| Kostfek vs Asuka | 10–16 | 38.46% |
| Kostfek vs Dragunov | 10–16 | 38.46% |
| Kostfek vs Reina | 16–9 | 64.00% |
| Kostfek vs Yoshimitsu | 15–7 | 68.18% |
| Kostfek vs Bryan | 7–13 | 35.00% |
| Kostfek vs Lars | 6–14 | 30.00% |
| Kostfek vs Victor | 8–7 | 53.33% |
| Kostfek vs Lee | 6–8 | 42.86% |
| Kostfek vs Xiaoyu | 6–7 | 46.15% |
| Kostfek vs Feng | 6–7 | 46.15% |
| Kostfek vs Leroy | 8–4 | 66.67% |
| Kostfek vs Alisa | 4–6 | 40.00% |
| Kostfek vs Raven | 5–5 | 50.00% |
| Kostfek vs Lidia | 1–7 | 12.50% |
| Kostfek vs Devil Jin | 2–4 | 33.33% |
| Kostfek vs Jack-8 | 2–3 | 40.00% |
| Kostfek vs Leo | 1–3 | 25.00% |
| Kostfek vs Claudio | 0–4 | 0.00% |
| Kostfek vs Shaheen | 1–3 | 25.00% |
| Kostfek vs Kuma | 2–1 | 66.67% |
| Kostfek vs Panda | 0–2 | 0.00% |
| Kostfek vs Zafina | 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.