The Cash Balance Plan is designed to make an allocation based on a defined term, specifically 

"Benefit Compensation."

Benefit Compensation is defined as essentially W-2 Compensation in excess of a fixed dollar amount minus bonuses.

The allocation formula creates an allocation of 10 times Benefit Compensation.

To learn more and view examples of using Benefit Compensation in a Cash Balance Plan, read this article by Dale Vlasek of McDonald Hopkins.