What is the meaning of "several boards and several eyes" (such as one board and three eyes) in opera?

Ban is a strong beat. The eye is the weak beat or the second strongest beat.

Traditional opera in Beijing Opera, for example, Beijing Opera has two reeds and three eyes of the plate style, meaning a plate three eyes, that is, a strong beat, three weak beat. The center eye is the second of the three eyes, which is the second strongest beat. This creates a strong, weak, sub-strong, weak beat rhythm, which is equivalent to the rhythm of 4/4 beat. Generally the second reed singing is board up, start in the strong beat.

Then again, the Xipi running water of the board is a board, forming a strong and weak rhythm of 2/4 beat. Xipi singing is generally eye start, which is often referred to as the weak beat start singing.