William Pitt came to power under his promise to win the Seven Years War. The first years of the war did not go well as French troops used guerilla tactics and were able to call on their Indian allies. Pitt, in order to ensure greater colonial cooperation, called for more reimbursement of colonial militias. This led to greater colonial involvement in fighting the war but would also lead to the heavy debt burden which would be detrimental to the relationship between Britain and the colonies after the war. Pitt also devoted more British troops to the North American continent as well as sending able leadership. One of the reasons why the tide of war changed in the American backcountry was British generals turning to colonial Ranger units to fight France's Indian allies on their own terms.
Perhaps the greatest strategy Pitt employed was fully utilizing the British navy to cut off supplies to New France. Once France could no longer be generous with their Indian allies, the allies became less enthusiastic for the war. Britain was able to resupply its armies at will while French forces in North America had to face shortages of food and ammunition. This more than anything led to the British victory in the war.