Can someone please explain this?

[Dunbar]

Originally Posted by my miss storm cat

Oh my God okay that makes sense but why is it called splitting?

"Splitting the variant" is probably not the best term for what's being done.

It's the race day that is split into 2 parts. You have one variant for the first bunch of races and a 2nd variant for the remaining races. (before and after a deluge, for instance).

A track that's drying out might have multiple "splits".

--Dunbar