What Phase?!?! Help Please

Hey I recently just ordered TUFFCUFF. It’s a lot of information but I finally got the routine and everything down. I just don’t know what phase to start on. It’s June so phase 1 seems like the obvious way to go. But does phase 1 increase velocity? By the way the book describes it, Phase 4 seems like the phase that adds the most velocity. Has anyone seen velocity jumps phase 1? Or should I just start with Phase 4? Thank you.