| Sans Undertale vs Steve | 9–13 | 40.91% |
| Sans Undertale vs Reina | 9–11 | 45.00% |
| Sans Undertale vs Law | 9–8 | 52.94% |
| Sans Undertale vs King | 7–10 | 41.18% |
| Sans Undertale vs Lidia | 10–5 | 66.67% |
| Sans Undertale vs Jun | 7–7 | 50.00% |
| Sans Undertale vs Clive | 11–2 | 84.62% |
| Sans Undertale vs Hwoarang | 7–5 | 58.33% |
| Sans Undertale vs Lili | 3–9 | 25.00% |
| Sans Undertale vs Heihachi | 6–4 | 60.00% |
| Sans Undertale vs Asuka | 4–5 | 44.44% |
| Sans Undertale vs Dragunov | 5–4 | 55.56% |
| Sans Undertale vs Lee | 6–3 | 66.67% |
| Sans Undertale vs Azucena | 5–4 | 55.56% |
| Sans Undertale vs Victor | 6–3 | 66.67% |
| Sans Undertale vs Eddy | 4–5 | 44.44% |
| Sans Undertale vs Bryan | 5–3 | 62.50% |
| Sans Undertale vs Devil Jin | 4–4 | 50.00% |
| Sans Undertale vs Jin | 3–4 | 42.86% |
| Sans Undertale vs Shaheen | 5–2 | 71.43% |
| Sans Undertale vs Leroy | 5–2 | 71.43% |
| Sans Undertale vs Kazuya | 2–4 | 33.33% |
| Sans Undertale vs Lars | 5–1 | 83.33% |
| Sans Undertale vs Kuma | 2–4 | 33.33% |
| Sans Undertale vs Yoshimitsu | 3–2 | 60.00% |
| Sans Undertale vs Xiaoyu | 3–2 | 60.00% |
| Sans Undertale vs Leo | 5–0 | 100.00% |
| Sans Undertale vs Nina | 2–3 | 40.00% |
| Sans Undertale vs Paul | 0–4 | 0.00% |
| Sans Undertale vs Raven | 2–2 | 50.00% |
| Sans Undertale vs Jack-8 | 1–2 | 33.33% |
| Sans Undertale vs Alisa | 2–1 | 66.67% |
| Sans Undertale vs Claudio | 2–0 | 100.00% |
| Sans Undertale vs Anna | 0–2 | 0.00% |
| Sans Undertale vs Zafina | 0–1 | 0.00% |
| Sans Undertale vs Fahkumram | 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.