The British soldier were well trained and had experience in war. The soldiers used the experience they had fighting in other battles. Their expereince was greatter than the Continental Army giving them a benefit.
The British had plenty supplies to last them for the whole war. They could make more and fund more money for the war with the taxes. They had supplies to last them throughout the war and could.
Distance Between Land
The British had a strong government they could rely onto. Their government was well funded so they could tax their people to fund for the war. The king could decide to put taxes and the British Parliament could vote for the taxes to be placed and the people agreed to them.
Soldier Were Indifferent
The British were't familiar with the land that well because it was new and far away. They didn't know where to attack and strategic points to attack the Continental Army. The British didn't know the quickest ways to get somewhere so they took the long paths.
The distance between England and the thirteen colonies was big and too far. It took the British too long to send supplies or troops which affected the outcome of the war. If the British were low on amunition then they had to wait a long time for new to come in.
The soldier didn't care about the war and just fought because the king ordered them too. The soldiers were tired from fighting in the war so they just wanted it to end. They didn't have the true dedication into fighting like the 13 colonies did.