Most resident surgeons start learning phaco with the divide-and-conquer technique for a good reason. This technique is not time dependent, compared to phaco chop where there is a small window of time in which to accomplish the chop while the phaco probe vacuum is holding the nucleus. In addition, sculpting the grooves de-bulks the central endo-nucleus so that the remaining quadrants are less than 25% of the total lens volume. For example, if I chop a nucleus in the bag into quadrants then each is about 25% of the lens volume. For divide-and-conquer the sculpted grooves removed about 20% of the lens volume so now each quadrant is more like 20% of the lens volume. This video has some important pearls to improve your divide-and-conquer techique.