| Mastadon vs King | 14–18 | 43.75% |
| Mastadon vs Reina | 15–15 | 50.00% |
| Mastadon vs Azucena | 11–8 | 57.89% |
| Mastadon vs Kazuya | 11–7 | 61.11% |
| Mastadon vs Dragunov | 4–14 | 22.22% |
| Mastadon vs Yoshimitsu | 8–9 | 47.06% |
| Mastadon vs Jin | 1–16 | 5.88% |
| Mastadon vs Bryan | 4–13 | 23.53% |
| Mastadon vs Hwoarang | 9–6 | 60.00% |
| Mastadon vs Steve | 8–7 | 53.33% |
| Mastadon vs Jun | 7–6 | 53.85% |
| Mastadon vs Eddy | 5–7 | 41.67% |
| Mastadon vs Lili | 2–9 | 18.18% |
| Mastadon vs Asuka | 8–2 | 80.00% |
| Mastadon vs Victor | 4–6 | 40.00% |
| Mastadon vs Paul | 3–5 | 37.50% |
| Mastadon vs Leo | 6–2 | 75.00% |
| Mastadon vs Alisa | 4–4 | 50.00% |
| Mastadon vs Anna | 4–4 | 50.00% |
| Mastadon vs Claudio | 4–3 | 57.14% |
| Mastadon vs Clive | 2–5 | 28.57% |
| Mastadon vs Feng | 3–3 | 50.00% |
| Mastadon vs Shaheen | 2–4 | 33.33% |
| Mastadon vs Law | 2–3 | 40.00% |
| Mastadon vs Jack-8 | 2–2 | 50.00% |
| Mastadon vs Lee | 3–1 | 75.00% |
| Mastadon vs Zafina | 1–3 | 25.00% |
| Mastadon vs Kuma | 2–1 | 66.67% |
| Mastadon vs Fahkumram | 1–2 | 33.33% |
| Mastadon vs Nina | 1–1 | 50.00% |
| Mastadon vs Panda | 0–2 | 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.