Dale sources The Cooperstown Cocktail from Old Waldorf Bar Days (1931), which reports that the drink was created at the hotel's Big Brass Rail bar for some money men from Cooperstown, NY. In The Savoy Cocktail Book (1930) the Cooperstown consists of equal parts dry vermouth, sweet vermouth and gin; the DDG version calls for a ratio of 1:1:4 of the same ingredients. Start by muddling a sprig of mint with the vermouths, then add gin and stir vigorously with ice. I like this drink because it is minty but not sweet (it is in fact rather dry) and feels like it is built on a classic structure.