One place to get some stats would be to use
https://avavt.github.io/gotstats/#/
but I think because OGS is struggling a bit, the api calls that that github page is using also aren’t loading.
When it’s back up though, I think I remember it being able to tell you how often you win as black and white on different board sizes and possibly by how much.
This would be the thread anyway for further suggestions and things for that site/github page.