Judging distance. After gun hunting for years I just couldn't judge the 20 or 30 yards for a bow shot. I got a range finder and use it toconfirm distances now. I'll guess how far a tree is then hit it with the rangefinder as practice. This has really honed my ability to judge distance. I missed a doe last year when I shot over her back. I thought she was a lot farther out than she really was. I got her the next day.