A 3-month-old female infant presents with a noticeable head tilt to the left. The mother reports a difficult breech delivery. On examination, a firm, non-tender mass is palpated in the mid-portion of the left SCM. Passive right neck rotation is limited to 10 degrees. The infant has mild flattening of the right occiput.

Based on the limited rotation (10 degrees), what is the predicted success rate for manual stretching?