I'd argue that they are the same. Calculating return value of B (return Math.max(2, someNumber)) is calling Math.max with two arguments, the second of which is explicitly named. The result is the same as partial(Math.max, 2)(someNumber). someNumber isn't used anywhere else, and the function itself just does the supplement of someNumber as second argument to Math.max . That's also what partial(Math.max, 2) does.