level set vs play ball

level set

• To establish a baseline of mutual understanding 

• An event consisting of level setting 

• The set of values x for which a real-valued function f(x) is equal to a given constant. 

• A state of mutual understanding among parties 

play ball

• To work together; to cooperate. 

• An expression used at the beginning of a game of baseball or softball. 

• To start anything tumultuous.