| Niellis vs King | 14–15 | 48.28% |
| Niellis vs Eddy | 6–20 | 23.08% |
| Niellis vs Jin | 11–14 | 44.00% |
| Niellis vs Steve | 12–11 | 52.17% |
| Niellis vs Hwoarang | 7–12 | 36.84% |
| Niellis vs Reina | 11–7 | 61.11% |
| Niellis vs Leo | 7–9 | 43.75% |
| Niellis vs Xiaoyu | 3–11 | 21.43% |
| Niellis vs Law | 5–8 | 38.46% |
| Niellis vs Feng | 5–8 | 38.46% |
| Niellis vs Bryan | 4–8 | 33.33% |
| Niellis vs Kazuya | 5–7 | 41.67% |
| Niellis vs Dragunov | 8–3 | 72.73% |
| Niellis vs Lili | 6–4 | 60.00% |
| Niellis vs Jun | 7–2 | 77.78% |
| Niellis vs Azucena | 7–2 | 77.78% |
| Niellis vs Lidia | 5–4 | 55.56% |
| Niellis vs Heihachi | 3–6 | 33.33% |
| Niellis vs Paul | 6–2 | 75.00% |
| Niellis vs Devil Jin | 3–5 | 37.50% |
| Niellis vs Nina | 3–5 | 37.50% |
| Niellis vs Yoshimitsu | 4–3 | 57.14% |
| Niellis vs Leroy | 3–4 | 42.86% |
| Niellis vs Victor | 4–3 | 57.14% |
| Niellis vs Lars | 3–3 | 50.00% |
| Niellis vs Shaheen | 2–4 | 33.33% |
| Niellis vs Claudio | 2–3 | 40.00% |
| Niellis vs Kuma | 2–3 | 40.00% |
| Niellis vs Clive | 2–3 | 40.00% |
| Niellis vs Fahkumram | 2–3 | 40.00% |
| Niellis vs Raven | 0–4 | 0.00% |
| Niellis vs Jack-8 | 2–1 | 66.67% |
| Niellis vs Asuka | 0–2 | 0.00% |
| Niellis vs Lee | 0–1 | 0.00% |
| Niellis vs Zafina | 1–0 | 100.00% |
| Niellis vs Anna | 1–0 | 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.