The question has arisen occasionally whether Boston Dynamics got their secret sauce from Bill, because he sent them some code and documentation at an early stage of their development.
Boston Dynamics has recently said that its robots use historically leveraged Model predictive control. “The legged robots we’ve built at Boston Dynamics have historically leveraged Model Predictive Control (MPC), a control strategy that predicts and optimizes the future states of the robot in order to decide what action to take in the moment.”
See the Wikipedia article on model predictive control.