Read Judges 20:36 Using Other Translations
So the children of Benjamin saw that they were smitten: for the men of Israel gave place to the Benjamites, because they trusted unto the liers in wait which they had set beside Gibeah.
So the people of Benjamin saw that they were defeated. The men of Israel gave ground to Benjamin, because they trusted the men in ambush whom they had set against Gibeah.
Then the men of Benjamin saw that they were beaten. The Israelites had retreated from Benjamin’s warriors in order to give those hiding in ambush more room to maneuver against Gibeah.