Washington flanked the British/some German troops by attacking when the british and german thought they were lost. The british partied and got drunk, and that's when Washington destroyed everything. Great victory for USA.
The Battle of Saratoga was important because it began international recognition by other countries. This just means that other countries acknowledged the 13 colonies as a country.
The french alliance assisted the Americans by sending a whole lot of money and supplies, and built coalitions along Netherlands and Spain across the pond. They also sent massive troops and ensured american victory.
The conditions were horrible at Valley Forge, nearly killing 2.5 K troops there, just by disease and weather.
Hope this helps.
