I use a 5 point scale that runs from 15 to 20. It could just as easily run from 0 to 5, but you get set in your ways.
It is, as above, elaborated with +/++ or - /--, which I think makes it kind of 20 point score anyway.
I use the plusses and the minuses to indicate respectively gosh/mmmm/but or potential or suspected technical flaws, or maybe a great beginning but a slightly questionable something on the finish, or variations and exceptions to the above. The problem of course is that I can't remember exactly, so I addend the score to a tasting note that I then lose when I fall asleep on the tube on the way home.
You have just made Marchbanks case.
My only problem with the KISS scale is that we now have 3 grades for wines we don't really like: Jesus Christ, Bof and Bof+; and only 3 grades for wines we do like: Good, Excellent and Oh Man !
Unless Marchy is a tougher marker and, for instance, would give Coudoulet 2016 a Bof+ instead of the Good I would give ?