fifty-fifty

In half: in two equal parts, shares, etc.

I'll handle production, you handle sales, and we'll split profits fifty-fifty.

Throughout our discussions and searching inquiries one object figured ever more prominently—the moon. We learned that it was technologically possible to develop a program to reach the moon, and we came to realize that since the Russians did not then have the ability to reach the moon any more than we did, we had at least a fifty-fifty chance of beating them there. Moreover, a moon-landing goal would give a dramatic focus to a space program designed to develop our skills and capacities on a broad technological front.

Half and half.

In this recipe, the flour and sugar are fifty-fifty.

In this recipe, the flour and sugar are in fifty-fifty proportions.

Used to describe two possible outcomes as being equally likely.

It is fifty-fifty that the employee who made the mistake will end up fired.

A challenge between two opposing players, where both have an equal chance of taking possession.

Ellipsis of fifty-fifty grind, a rail or edge grind, using both trucks to grind along, longitudinally aligned.

Ellipsis of fifty-fifty slide, a rail slide where the snowboard is longitudinally aligned with the direction of the slide, down the centerline.