It was a gorgeous day today with a lot of sun!  I took my 5 1/2 year old Labrador, Sackett down to Marymoor dog park and worked him on double marks, holds and triple marks.  He sits next to me and I throw bumpers out for him to retrieve.  I throw one out to the left and then second to the right or some other crazy combination.  He is not allowed to get them until I release him with "get it".  He should retrieve them in order from last to first.  He has doubles down, but is still challenged by triples.  He keeps forgetting the middle one.  The other thing I worked on was having Sackett sit and stay while I move about 30 yards away before throwing the bumper.  He stays at the original position until I release him to get the bumper.  The entire time he is in a hold, whether it is by my side or at a distance, Sackett is like a coiled spring.  He is so excited to retrieve that his muscles are quivering.  When I release him it is like pulling the trigger!  He takes off at full speed!