| Undertow vs Bryan | 39–49 | 44.32% |
| Undertow vs King | 33–41 | 44.59% |
| Undertow vs Kazuya | 24–45 | 34.78% |
| Undertow vs Jin | 33–26–1 | 55.93% |
| Undertow vs Steve | 23–31 | 42.59% |
| Undertow vs Heihachi | 21–21 | 50.00% |
| Undertow vs Eddy | 18–16 | 52.94% |
| Undertow vs Devil Jin | 10–17 | 37.04% |
| Undertow vs Lili | 12–15 | 44.44% |
| Undertow vs Lee | 14–13 | 51.85% |
| Undertow vs Yoshimitsu | 6–20 | 23.08% |
| Undertow vs Azucena | 11–14 | 44.00% |
| Undertow vs Lars | 10–13 | 43.48% |
| Undertow vs Hwoarang | 8–13 | 38.10% |
| Undertow vs Reina | 2–18 | 10.00% |
| Undertow vs Victor | 12–8 | 60.00% |
| Undertow vs Law | 6–12 | 33.33% |
| Undertow vs Dragunov | 5–13 | 27.78% |
| Undertow vs Jack-8 | 7–10 | 41.18% |
| Undertow vs Clive | 6–8 | 42.86% |
| Undertow vs Claudio | 5–8 | 38.46% |
| Undertow vs Paul | 3–9 | 25.00% |
| Undertow vs Leroy | 5–7 | 41.67% |
| Undertow vs Asuka | 8–3 | 72.73% |
| Undertow vs Anna | 1–9 | 10.00% |
| Undertow vs Fahkumram | 4–6 | 40.00% |
| Undertow vs Jun | 3–6 | 33.33% |
| Undertow vs Lidia | 3–6 | 33.33% |
| Undertow vs Leo | 3–5 | 37.50% |
| Undertow vs Feng | 1–6 | 14.29% |
| Undertow vs Alisa | 3–4 | 42.86% |
| Undertow vs Kuma | 3–4 | 42.86% |
| Undertow vs Zafina | 4–1 | 80.00% |
| Undertow vs Raven | 2–3 | 40.00% |
| Undertow vs Xiaoyu | 0–3 | 0.00% |
| Undertow vs Shaheen | 0–3 | 0.00% |
| Undertow vs Nina | 0–3 | 0.00% |
| Undertow vs Panda | 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.