You really have to worry about how much water (no other types (gatorade, soda, etc) only if you are sweating PROFUSELY. Like, if you are playing under 100 degree weather. In this case, you just need to add gatorade to your drink.
The reason is that our blood has other electrolytes such as sodium and potassium. And, they have to be in certain balance with water in our blood otherwise, it can cause some problems. When you sweat A LOT and drink only water, you are basically diluting your blood.
In other words, you really don't have to worry about it because you will be too full to drink anyway. If you want exact amount it's about 3 liters.