Aside from the inherent probability in the coin, it is also possible for the coin flipper to exude bias if the coin is caught.
I can time a coin catch to get 75-25 heads.
Don’t let someone catch the coin if they flip it.
I can time a coin catch to get 75-25 heads.
Don’t let someone catch the coin if they flip it.
https://bar-tricks.wonderhowto.com/news/win-coin-toss-every-...
If you're doing the same throw and the same catch each time, it just becomes muscle memory (again, like playing an instrument) and you can get a good success rate.