I've spent a lot of time researching and studying the "false rut." In essence, it's the idea that does "smell" right one estrus cycle (28-30 days) before they actually do come into estrus. This early "smell right" cycle usually lasts for only 4-5 days, but during that short timeframe, bucks kick into near full rut mode, producing a short-lived flurry of rut activity, such as scraping and rub-making as well as full-blown chasing.
Not every location will see a false rut, and the intensity of the false rut can be highly variable from year to year. In fact, in areas that do regularly experience a false rut, on occasion the false rut can be so strong as to produce more daylight rutting activity than is produced by the real rut a month later.