In this question, I am assuming you are asking about the British military strategy in the first few years of the Revolutionary War. I will base my answer on this premise.
In the beginning of the Revolutionary War, the British had two goals. One was to control the rivers and the coastal areas. The other was to isolate the New England colonies from the rest of the colonies.
To accomplish the goal of controlling the waterways, the British blockaded our coast. They attempted to prevent supplies from entering and leaving our country. Since our navy was so small, the British were successful in doing this. The colonists tried to weaken the blockade by sneaking some ships through and using privately armed ships, but the British navy was too powerful for this to work. The British were successful in controlling the coastal areas.
The British developed a three-part plan to isolate the New England colonies from the rest of the colonies. General Howe was supposed to move his army from New York City to the area near Albany, New York. General Burgoyne would move his army from Canada to the area near Albany. The army of Lieutenant General St. Leger would join these armies. Together, they would fight the colonial army, and if successful, isolate New England. However, the plan failed. General Howe didn’t follow the plan and went to Philadelphia instead. St. Leger’s army was defeated. General Burgoyne moved so slowly, he constantly gave the colonists time to regroup and reorganize. Since General Burgoyne’s army was the only one to arrive near Albany, the British were eventually surrounded by the colonists and lost the Battle of Saratoga.
As a result, the British weren’t able to successfully implement all parts of their plan in the first few years of the war.