1/3 a fluid ounce or 1 centilitre of Jack Daniel's Whiskey
1/3 a fluid ounce or 1 centilitre of Jim Beam Bourbon Whiskey
1/3 a fluid ounce or 1 centilitre of Jose Cuervo
1/3 a fluid ounce or 1 centilitre of Captain Morgan's Spiced Rum

Spread the shots out in front of you, take the first one, slam it, then the next and so on down the line. No chaser, no pause. When all four are down, guess which one was which.