When you prune an apple shoot by cutting into last years growth, you remove the apical bud and eliminate the apical dominance that it had over the lateral buds just below it on the shoot. This type of cut is also called tipping. Removing the apical bud in the dormant season (November through March) usually results in the upper most buds just below the cut growing into 5 to 7 new branches as in the attached pictures. These new branches quickly reestablish apical dominance over the buds lower down on the shoot. The uppermost bud grows into the most vertical dominant shoot. The next bud (sometimes the next two) usually develop a sharp upright angled connection with the trunk of the tree. Sharp upright angled branch connection are weak connections that are likely to split in the years to come when there is a lot of weight from the branch itself, fruit, snow and wind. These more upright branches are also more vigorous than flatter angled branches resulting in the production of fewer flower buds.
The third, fourth and fifth shoots usually develop into flatter angled branches with strong connections to the tree trunk (or main stem) and weaker growth. These weaker growing flatter angled branches are the most desirable type of future structural and apple producing branches.