Interpretation of “Sun Tzu’s Art of War”: How to know its strength without testing it?

Anywhere, there are more than enough.

Chen Changwen’s interpretation:

A tentative contest against the enemy, so as to know the strength of the enemy.

Try,

Use your own troops to tentatively hit a dozen, feel and analyze the strength of the enemy .

How to know its strength without testing it?

Source: Chen Changwen Business Wisdom