How did George Rogers Clark outwit the British when he captured the Ohio River Valley?

He tricked the British into believing he had a large army by having his men yell and scream as they attacked the fort. The British quickly surrendered
George Clark outwitted the British at Fort Sackville in Vincennes (in today's Indiana) by convincing them he had more soldiers. He also discouraged the local Native American tribes from aiding the British by having four captured Natives publically killed. The British surrendered the fort.
George Rogers Clark outwitted the British by making them surrender a fort because they believed Clark had them greatly outnumbered. He did not. His victory kept the Northwest Territories out of British hands.