Originally Posted by RigglePLC
Why are you overseeding? What is the goal? Best to resod thin spots with a sod similar to your original. Do not put a different type or lower quality of grass in the thin--or dug up--spots. Stay with sod-quality Kentucky bluegrass where it was sodded, and sow top-grade perennial rye in the back where it was hydroseeded. If your grass is already thick, not much of the seed will "take" and if it does--you will not be able to tell. Concentrate on the thin spots or anywhere soil is visible.
I disagree riggle. Patching turf with sod or seed will likely lead to a patchwork turf of variable colors & textures if you aren't matching what is there exactly. IMO, when any seed goes down, it should go down over the entire area, no exceptions. A patch with sod should be attempted only
if it is an exact match.