There isn't one number. Lets extend this to an easier subject we all have extensive experience with... evaluating the taste of the food we're eating. If the f

There isn't one number. Lets extend this to an easier subject we all have extensive experience with... evaluating the taste of the food we're eating. If the food critic fad of the day prioritizes flavor balance, the "winner" will have an amazing balance of flavors but perhaps the texture will resemble dog food or clam chowder. If the food critic fad of the day prioritizes texture, or heat, or visual appearance, or smell, or sweetness (well, food critics don't like corn syrup but walmart shoppers certainly do...). Even worse, fads aren't binary either, its all a big ratio. That's at least partial explanation why some authors go in and out of favor in lit over centuries. Its actually a lot of work in lit to keep up with who is supposed to be cool and who is supposed to suck based on changing tastes. Then dog pile a ton of groupthink on top with some politics and inevitable cultural issues (racism, nationalism, etc) and you can see how faddish some of this is. On the other hand, if you have an agreed upon definition of impressionism, then you can evaluate who makes the best impressionist painter under that set of carefully defined rules. I think it would be hard to argue against Monet. Someone could claim Sisley but I think on long enough study that Monet beats Sisley overall. (edited to emphasize, beats Sisley at the defined rules... nothing wrong with liking a set of rules where Sisley beats Monet, just don't name that set of rules impressionistic painting) Or, you can compare your Robert Frost to this dude named Robertson who wrote similar, yet somewhat inferior poems. I think it would be a lot of work or outright impossible to compare Frost to Kipling or to T S Elliot beyond sorta "and heres a different genre"