you could try this for distance, firstly get down to dogs height and see what they see gives you insight into what they view when a dummy is thrown,,,,using canvas dummy add some pheasant scent if you wish,,sit dog at heal on lead call mark and throw dummy out, now both walk forward and find dummy lift and walk back,can all be on lead,repeat few times then do off lead starting with short distance and build up to longer therefore learning a longer retrieve also rem to always hunt downwind for hidded retrieve increases chance of finding,,,
simple back command,,,,,,,on laneway or path drop dummy at side call mark and then continue walking,turn call mark and send for retrieve while shouting back againing increasing distance and dog associates word back with the running back to get dummy,,,if that makes cence...lol you may have read bout the three card trick for going back recon this is waste of time great to show off with but not of much use in the field,,this is much simplier back...
just rem a cocker aint a lab and therefore they dont do hundred yard retrieves and personally i dont want mine to either.... leave those for the lab men on the shoot.......