knight's tour

Here's a place to download the famous "knight's tour" puzzle. Believe it or not, it can be done, although i've only been able to leave 10 squares untouched on chessboard. The site shows you how to do it. I wish i hadn't seen it because i'd like to work it out myself. I also believe it can help your game, since you have to visualize many moves ahead where that knight is going to land. Here's the site: http://www.chessville.com/misc/knightstour.htm