Here is how it was explained to me at one time. For a Right Hand BackHand thrower.....
If you aim straight at the basket and throw the disc flat (at the speed needed to make the disc perform as it is designed to)....
A 'stable' (0 turn 0 fade) disc will go straight to the basket, with a slight bit of fade at the end. Ending near the basket.
An overstable disc (for example, 0 turn 2 fade) will go straight towards the basket for a while and then fade to the left - more left fade than a 'stable' disc; ending up left of the basket.
An understable disc (for example -2 turn 1 fade) will start off going to the right of the basket but then have a bit of left turn at the end; still ending up to the right of the basket.
The numbers are important to give an idea of how what the disc does. A -1/1 will start off to the right of the basket and then come back left....because the numbers are the same (both 1's), it should end up back at the basket. The larger one of the number is, the more the disc will go that way.
Again, that is only true if you throw the disc at the intended speed and spin with no wind; and flat. Add a wind and the disc will react differently, change the speed and/or spin....the disc will react differently. Add hyzer angle or anhyzer angle...the disc will react differently.
snow rider 3d
You should only use the numbers as a guideline....you won't know what the disc actually does until you throw it.