Note that Wine is one of those confusingly-versioned projects where 4.20 is the one that comes after 4.19
Some software increases the x before that though.
I think Windows 3.1 to 3.11 was another example of decimal version numbering, instead of calling it v3.1.1.
The equivalent in the more common versioning scheme would be 2.8.0 which would then also be called 2.8.
How I currently understand is its just 2 numbers and 2.8 is a simplification for meaning 2.8x.