Either George won OR the British gave up? You could tie yourself into mental knots here, trying to make this go one way or the other, because there was a good bit of both involved.

The British objective at first was to get the colonists to comply with British taxes and tariffs, and agree to the settlement limits imposed after the Seven Years War. Those efforts met with resistance, and as that resistance was met with punishments ( like the Townsend Acts) the resistance, centered in Massachusetts, grew into a revolt.

Stifling that revolt meant defeating the rebel forces. This turned out to be difficult, because Washington could ( and did) operate over a very large territory and the British forces were limited in size. After the defeat at the Battle of Long Island, Washington avoided decisive battles but was able to continue to pose a threat and take advantage of an opportunity- like when he crossed the river at Trenton (much of the time his army was very poorly supplied, and if the French had not supported the revolt, it's quite likely that eventually his force would have become ineffective, and he would have been unable to take advantage of any opportunities, but that's speculation).

Stifling the revolt meant gaining control of the rebels' territory. This the British were also never able to do. Initially, the British also hoped to suppress the revolt in Massachusetts. But in doing so, they alarmed the other colonies and the revolt spread. They had hoped to have more Loyalist support in the southern colonies, but after offering freedom to all slaves who would oppose the rebellion, they lost that. Because their forces were limited, they were also unable to provide security to Loyalists . In North Carolina, for example, they were happy to ask for Loyalists to help defeat the rebels, but couldn't find and defeat the rebel forces, and weren't there to intervene when those Loyalists were themselves attacked by the rebels.

Eventually, Washington was able to take advantage of a big opportunity at Yorktown, aided by a French blockade. That really was a win for him and a defeat for the British. But you could also say that the British didn't try that hard to fight the war, didn't land a big army, aided by a big fleet. That's somewhat due to the fact that those colonies were not particularly important. If the Caribbean sugar-producing colonies had tried to revolt, they likely would have devoted more time and effort. The British were also fighting elsewhere. They had just finished the Seven Years War ( that Washington had managed to ignite) and were into the series of wars which would eventually result in their taking over India. So, yes, the British also gave up. That would happen again in the War of 1812, where the British were winning almost everywhere they went, but , having to fight Napoleon in Europe, very quickly came to terms favorable to the Americans.

So, if you want to keep to your original question, you would really have to ponder percentages...you know, Washington defeating, 60%, British giving up, 40%. Or the reverse. Sorry if it's not simple. History is like that.

Don Higginbotham: The War of American independence