I remember in the Revolutions podcast by Mike Duncan that his summary of Washington as a general was that he had overly ambitious battle plans that required too much coordination and timing to work as he wanted, especially with a primarily militia force but he could extract his forces in the blink of an eye and his men were loyal enough to him to charge into hell itself. As such even though he didn't win every battle he always had the men to keep trying which worked well in wearing the British down.
Eh, from what I remember of my AP us history, he wasn't that great of a battlefield commander and often lost or was forced to retreat from his larger engagements. However the RW wasn't about winning every battle and this is where Washington should be commended.
He is given tons of credit for his excellence logistical skill set, even with next to no supplies, disease, and the fact most of his men were not even being paid for their service he still found a way to keep his men focused and dedicated.
To put it bluntly Washington was the best at retreating and given the RW's intention of spreading the british forces thin, this strategy proved effective.
His successes can also be attributed to his excellence command staff, and although we can't blindly believe what we know about GW supposedly he was an excellent judge of character and ability. His generals and commanders were often accomplished leaders themselves