keep at it mate,but i would do this no more than 3x a day,for my pup i done this for about 2 mths,when he is getting confident bringing it back to you,move back a little further so that he has to retrieve it back longer,he will have his off days,when this happens just give him a break for a day or 2,always give him loads of praise and end on a good note,patience and little and often are the key,this worked for me,other may have done it different,hope this helps,cheers......john