your forgetting that a grey can out sprint a lurcher ( i pitted my last bitch against many a lurcher in races and it left them for dead ), granted a lurcher generally has more stamina , but a grey can catch the quarry up faster, even if they have only one or two goes before they are tired. ive had a few ex track dogs, and it all depends on how much time you spend on them , they arent stupid like your lead to believe , they just have one thing on their mind ( catch that rabbit ) which after all is what they have drummed into them for racing