| Byron Mashima vs Bryan | 20–15 | 57.14% |
| Byron Mashima vs Jin | 13–14 | 48.15% |
| Byron Mashima vs Hwoarang | 13–11 | 54.17% |
| Byron Mashima vs Yoshimitsu | 14–8 | 63.64% |
| Byron Mashima vs Lili | 9–13 | 40.91% |
| Byron Mashima vs King | 9–12 | 42.86% |
| Byron Mashima vs Steve | 10–9 | 52.63% |
| Byron Mashima vs Paul | 9–9 | 50.00% |
| Byron Mashima vs Jun | 8–9 | 47.06% |
| Byron Mashima vs Kazuya | 14–2 | 87.50% |
| Byron Mashima vs Nina | 9–7 | 56.25% |
| Byron Mashima vs Reina | 6–6 | 50.00% |
| Byron Mashima vs Dragunov | 6–3 | 66.67% |
| Byron Mashima vs Lee | 3–6 | 33.33% |
| Byron Mashima vs Xiaoyu | 0–7 | 0.00% |
| Byron Mashima vs Asuka | 3–3 | 50.00% |
| Byron Mashima vs Feng | 5–1 | 83.33% |
| Byron Mashima vs Leo | 2–4 | 33.33% |
| Byron Mashima vs Devil Jin | 2–2 | 50.00% |
| Byron Mashima vs Lars | 3–1 | 75.00% |
| Byron Mashima vs Alisa | 4–0 | 100.00% |
| Byron Mashima vs Azucena | 0–4 | 0.00% |
| Byron Mashima vs Eddy | 1–3 | 25.00% |
| Byron Mashima vs Jack-8 | 2–1 | 66.67% |
| Byron Mashima vs Zafina | 0–2 | 0.00% |
| Byron Mashima vs Victor | 2–0 | 100.00% |
| Byron Mashima vs Heihachi | 2–0 | 100.00% |
| Byron Mashima vs Law | 0–1 | 0.00% |
| Byron Mashima vs Kuma | 0–1 | 0.00% |
| Byron Mashima 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.