In the American Revolution two totally different armies from two totally different countries and cultures collided in a war to settle the freedom of a nation in the making. This setting made for some sloppy warfare, but more importantly it showcased the advantages and disadvantages for each side.
The British armys main weakness was its leadership, not a lack of leadership or even a lack of leaders, just the wrong guys in the wrong place. Advancement in the military was based on connections, money, and seniority. This allowed people of no experience or skill to buy their way into positions of great power. This is evident with leaders such as Germain, and Montagu, who were either incompetent and inexperienced or corrupt and unmotivated. Contrary to popular belief George III was able to command and lead his country but had very little decision making power. This impotency did not stop at the high-ranking decision-makers. Many of the generals in the colonies were weak and poorly suited to do battle. Several experienced and respected generals, like Gage and Howe, were unsuccessful due poor decision making and an admitted lack of imagination and extreme cautiousness. Then there were other generals who were very able but due to their enormous egos ended up failing in important situations. The only very effective general on a constant basis was Cornwallis, and even he couldnt deliver when it counted.
On the other hand as you go down the ranks of the British military the ability of the soldiers got better. The infantry and cavalry was the best trained and finely tuned organizations of military in the world at that time. This was a terrific advantage when they actually got into traditional battles with the Americans poorly trained and inexperienced fighters.
On the American side of the fighting things werent much better. American leadership was mostly self-taught generals who were desperately inexperienced and un-skilled, but knew how to motivate their soldiers to fight for their freedom and their country. This type of inspirational leadership allowed generals like Mad Anthony Wayne to impact the war in such a manner that won it for the Americans. Although out numbered and out skilled the Americans had the environment on their side. They profited from having the advantage of being the host of the war on the defensive. They could have faster and more abundant supplies and resources from the surrounding land. They were more familiar with the territory, and more effective in a guerilla type of strike and retreat warfare. These types of tactics, combined with the surroundings and intense magnetic leadership of Generals George Washington, Anthony Wayne, and Benedict Arnold, and foreign assistance from the skilled and knowledgeable French, Poles and Prussian leaders, eventually won the war for the Americans.