Good afternoon,
It looks like the match is being used in the Column Reference portion of the Vlookup formula. So, it is finding A4, in the range Division1&2 season 42 B:AF and returning the column returned by the match formula which is finding b1 in the top row of the same sheet. It might be cleaner if you used an index-match combination. You could use:
= Index( Division1... B:AF, match( A4, Div... B:AF, 0), match( B1, Div... B1:AF, 0))
This will do the same thing, but it's a bit more straightforward. It makes kind of a matrix out of the table and then finds the matching row and column and returns the result.
Hopefully this is easy enough to understand. Best of luck,