Well I guess the best way to explain this to you would be to go out side and dig the ground bare with a rake or your foot and then look at the ground. It should appear to be slightly wet and possibly dark in color. Now as the sun dries it out it will appear a lighter color.
So learn the difference between a fresh scrape and a scrape that may be old. A buck will visit his active scrapes and dig them up from time to time, during the rut, so keep an eye on any scrape that you find.
If you want him to get angry, go buy some buck urine and pour some in his scrape. The next time he visits, he will really tear it up, hopefully you will be somewhere close by and get a shot at him, or at the very least, get a chance to observe his behavior.