Is this allowed?:
I was able to do this in
@vletm 's file, but that file wouldn't open properly with Excel complaining it had to repair it and remove some data validation, but I don't think it mattered because
@vletm 's code adds and removes its own data validation, but maybe something else was damaged - perhaps to do with
@vletm using a Mac?
Anyway, the attached doesn't allow what's in the picture above, but even if you should try to override the data validation it will still highlight errors.
This has been interesting challenge and one where I experimented with the newish FILTER and UNIQUE functions - hard work using the vba version of the sheet FILTER function! It's probably easier to use traditional looping as
@vletm has done, although his code may need a tweak if the above picture is a situation which should be prevented.
My code could be shorter but I haven't bothered.
24 teams and 17 weeks could occupy 204 rows with each team playing only 1 match per week but I have included data validation and conditional formatting up to row 500 on
Sheet1.
I
think I've prevented all undesirable combinations via the drop downs, however if someone can point out any mistake I may have made I'd be glad to revise.