What advantages did Britain have over colonists?

The British had many advantages during the American Revolution. British troops were some of the best trained in the world, and they initially outnumbered the colonial militias. The British were also better supplied and better fed, unlike the colonists who struggled to raise money for the war effort. The British had the capability to finance the war, while the Continental Congress didn't even have the power to raise taxes. The British also had the best navy in the world, which was critical in transporting troops.

To sum it all up, the British had a larger, better trained army and more money. It was an established empire fighting a group of rebels. Unfortunately for the British, they were already fighting other wars, and the entire populace of the colonies could not be pacified by even their sizable force.