"Brilliant" is a bit of a tough term to define, as, for that matter, is "strategy". A colonel lecturing at the US Army War College in 1939 pointed to a previous writer who "quotes nineteen different definitions [of strategy] and then makes up one of his own" (Weigley, xvi). However, I'll take the question in the spirit in which it is intended, while giving a more general answer which fits the general nature of the question. Broadly, historians tend to agree that in terms of keeping the Revolution going, Washington was an outstanding...something. They often disagree as to what, exactly--general, politician, moral force, etc. I'll use a source which answers your question very directly here, rather than delving into multiple obliquely related narratives.

Russell Weigley, in his The American Way of War: A History of United States Military Strategy and Policy, spends a chapter focusing on Washington and his strategy. He points out that GW's strategy was shaped by a military poverty which created challenges that were very different from what modern American commanders face. Thus, he took on the strategic defensive as his main technique for winning the war, which in turn put him in a position to avoid and even lose battles in an effort to keep the Continental Army, and consequently the Revolution, intact. His hope was that by making the war costly, and--later, once it became an option--depending on France to do the heavy lifting abroad, he would be able to convince the British to just...go away. On what may be considered a strategic level as well, Weigley states that GW was an abysmal cavalry general (in part due to lack of same) and an outstanding chief of intelligence--perhaps the best battlefield commander to ever serve in that role in the US military. Weigley concludes that while Washington's strategy may have prolonged the war needlessly, it worked, which is the ultimate measure of effectiveness. So, brilliant strategist? Perhaps, in some regards. Competent strategist? Certainly. If you ask a more specific question you may get more/better information for your intended result.