Rolling 10 will grant you maximum possible distance of the selected club. Each club has minimum and maximum distance - this is indicated by the two dashed circles.
On top of this, there is always "random" variations of the distance and angle based on starting terrain (smaller chance of clean hit), club and landing terrain - ball can roll after hitting the ground and will roll more on fairway/green then on rought grass / sand.
Also, the randomness is larger for higher numbers rolled and there is bigger chance not to swing perfectly. This is intentional as it is more true to reality...
Maybe this should be more deeply explained in the help.