In 2013 I tried for Loretta's in 14-24. Spent $1,000 just for regionals. I thought I was prepared, in the gym once before work and after work 7 days a week, dieting, riding every night (I was getting faster) but they had regionals at baja that year and I never rode sand once in my life except for Indian mound, which was more clay/sand based dirt. I went up there and got smoked! So my advice is to practice on more than just dirt, bc I think baja has the qualifier again this year, and if so, you need a soft compound tire (mx32) and a sand/mud tire (mx11) anything is possess long as you really want it