I have a document from a research study on penned deer from the Texas Parks and Wildlife department that kinda backs that up. Keeping in mind that there are always outliers, the 168-page report basically says if they are not at least forked horned their first year they will never grow into a quality deer. And every 1.5-yr knob head or spike should be removed from the pool.
I have the report in PDF, if you would like a copy PM me. It is an interesting read with neat pictures of antler growth based on varying diets and fist year antler growth.