You gotta make sure you're twirling that string around with enough speed to keep the tension on it, but not so fast as the top wants to fly out, or slow enough where the tip will slip out of the wraps due to lack of tension. The transition can be a bit tricky at first until you can maintain relatively consistent speed between the Over/under and through the zone between the two. For me, it was slowing down and getting slack and the top flying out of the wraps. Rotations 1 and 2 would be good, but then it would fly out on 3 during transition, usually off to my right(I play right handed).