I MUST NOT KNOW ANYTHING ABOUT RUNNING DOGS THEN IF YOU START OFF A LINE BY CROSSING BULL OR COLLIE WITH A GREYHOUND THATS FAIR ENOUGH YOUR BLENDING QUALITIES LIKE STAMINA AND GOOD FEET FROM THE COLLIE OR BULL THAT THE GREYHOUND LACKS, WITH SHEER PACE WHICH THE GREYHOUND HAS BUT THE COLLIE OR BULL LACKS. BUT IF A LURCHER ALLREADY HAS GOOD STAMINA PACE FEET ETC WHY TAKE A STEP BACKWARDS BY ADDING MORE COLLIE OR BULL TO THE MIX AT THE RISK OF LOSING SPEED? WOULD YOU ADD PURE BULL OR PURE COLLIE TO YOUR LURCHERS AND EXPECT THE PUPS TO BE AS FAST OR AS GOOD AS THE PARENTS?