Liver shots arethe most complex hits on a deer. Some go 80-100 yds good blood all the way and die in a short time. Other times they are still alive after 4 hours.
On a gut shot, catching liver can sometimes give you just enough blood to trail them(assuming hole doesn't plug) and assuming you give them proper time to lay up and die. Even liver/1lung shots can be tricky and you better give the deer time or you could push it and lose it.