with the B+F or Ortovox systems the numbers can go crazy because the box is taking and up,down,north,south, east and west measurement everytime the numbers change. They can get confused by fast movement.
if the dog is flying backwards and forwards or twisting around quickly, the numbers will fluctuate, wildly!
with a bit of use and experience you'll know exactly whats happening, wether the dog is just digging and pushing on or is coming under a lot of pressure and needs you to get the shovel moving.
if you find yourself coming down to the left or the right of the dog often, then extend you