1. The pitcher makes his natural pitching motion but fails to pitch to home.
  2. The pitcher fakes a throw to first base, while touching the rubber, but fails to make the throw.
  3. The pitcher fails to step directly toward a base (45 degrees) before throwing to that base.
  4. The pitcher throws or fakes a throw to an UNOCCCUPIED base, except for the purpose of driving a runner back that is attempting to steal that base.  This is an umpire judgement.
  5. The pitcher makes an illegal pitch
  6. The pitcher makes any motion naturally associated with the pitch while they are not touching the rubber.
  7. The pitcher fakes a pitch without the ball; it does not matter whether he is on the rubber or not.
  8. The pitcher, after coming to a legal pitching position, (usually set) removes one hand from the ball.
  9. The pitcher drops the ball while on the rubber
  10. The pitcher delivers from the set position without coming to a discernible stop. A change in direction is not a stop.
  11. The pitcher turns his shoulders toward first base after coming set.

These are some common ways to BALK a pitcher!