,Thinning Fruit will Result in Larger Fruit
Most home growers don't thin enough, it generally takes a couple of seasons to thin fruit properly. Thin out the smallest and damaged fruit by spacing fruit every 4-8 inches. It is recommended to leave 1 fruit per spur. Always select the largest fruit to leave.
Fruit thinning will not only pay off with larger mature fruit, it is healthier for the tree. It will prevent limb breakage, as maturing fruit becomes heavy. Thinning will also benefit next year's bloom. Additional information found at Backyard Orchard.
Source: California Master Gardener Handbook Second Edition