More to the point - this is a vodka greyhound… Like many cocktails that we enjoy today with vodka as their base spirit; they would have been originally made with something else. In this case the greyhound was originally made with gin. You can make it either way - in fact you should try both and see which you like better. If the grapefruit juice is to sour for you, feel free to add some sugar.
Ingredients: 1½ oz Vodka grapefruit juice Glass: Collins
Method: Fill the collins glass with ice. Add the vodka, and top off with grapefruit juice. Stir and serve.