Last year I tracked a doe I hit a bit far back. I got 1 lung and liver. She went about 150 yds I think. Not far really but the blood was sparse at times. I had read Rob's tracking thread over and over. It payed off for me. The emotions I felt that day were indescribable. Elation at the shot turning to concern at watching the doe run off out of sight. 2 hours of self doubt during the trail punctuated by moments of heart pounding excitement when I found the next spot of blood. And then the culmination....the pride and gratitude I felt when I found that doe lying under a mesquite.
That is the only deer that ever gave me a problem finding it. I doubt it will be the last but it was more rewarding than almost any other deer I have ever killed.