text: I am making something to automatically cast spells at enemies on League of Legends.
  
  I am able to get the 100% precise interpolated position of the enemy where he'll get hit by my spell, if he stays on his path, and if i cast my spell towards this position.
  
  In order to not waste my spell i want to create a hitchance system. If the hitchance is too low, i won't cast my spell and preserve it until the hitchance is high enough.
  
  I have informations about enemy current and old paths. A path is an array of vector2d, those vector2d are basically just waypoint that the enemy will follow.
  This shouldn't use artificial intelligence or machine learning.
  The start position of my spell cannot change, it is fixed.
  The end position of my spell will always be the interpolated position of the enemy, as a spell always move in a straight line.
  The enemy speed cannot change, so it is useless to use it for this.
  
  Please help me write this hitchance system, it should just tell me how likely the enemy is gonna stay on this current path, because if he moves, it's likely that it'll miss if he's reactive enough. I want it to be percentage based ( between 0.1 and 1, 1 being impossible to dodge, 0.1 very unlikely to hit ) 