There is a large set of fields across from here. I do much the same. I have different weight/length of chains dropped along the edges of the fields. I use these fields for long walks with and without the chains. I promised pics in another post about brood boxes but I am digitally challenged to say the least. I will try to get a pic of the cable set up I use as well. I like the mills as much as the next guy, I like anything that works, but I have learned there is something special about a dog giving every thing he has in an all out sprint with his four feet on the ground. I 'think' it quickly separates itself from other methods. EWO