I think it depends. If your schtick is manipulating probability, then yeah, it'd basically be the entropomancy described in the book with various curses.
If you're more into reading probability, then it could go with either Ritual or Channeling. Ritual in particular would let you do short-term divinations based on your predictions, while Channeling would be the sort of stuff mentioned earlier, including your direct blast (which isn't an actual blast of fate-manipulating powers so much as it is incredibly rapid prediction and action to remarkable effect).