If i'm not sure and get mixed advices from people, then I experiment by my self. This is the best way to find true answer...I figure every way you do it results in lost seed and some results in more lost time with less lost seed and less lost time and more lost seed. I'm sure the fate of some seeds is exactly as you describe, but for every seed that drops 3 inches down a hole, there are others that don't land that far down or actually germinate on the soil layer above from the cores melting. and then a whole bunch of others that don't do anything.
That said, i'm getting ready to do this in NE Wisconsin and I do have a question. Last time I did this I rented a slice seeder and it was not a great experience to say the least. So i'm going with aeration and overseed this fall.
I am cutting at about 3 3/4 right now, but temps are starting to cool some. No more 90's. Just 70's and 80's. Soil temps are still about 70 degrees so should get quicker germination. But i've been reading around, I have the aerator rented for next weekend. do I just go right from 3 3/4 down to 2", aerate and seed?
Or would it be better to make take 3 cuts between now and then giving a day or 2 in between and take it from the 3 3/4 down to 2 a half inch or so at a time? and then aerate and seed.
Next question. Some say keep cutting at the 2" so seed gets better sun and warmth others say don't cut until it's 4" or more? I'm inclined to keep it around that 2" mark, but not sure.
only the .5 acres immediately around the house, the rest is relying on nature. Less than perfect I know going in and a roll of the dice. we're usually wet enough thru fall that it will still work ok.Are you going to irrigation available to water daily? That would be the most important key in answering your question.
Going from 3 3/4” to 2” is going to put extra stress on the existing turf if you do it all at once. So mowing 3 times and lowering taking the 1/3 rule into account would be the best approach. I would take it even down to 1 1/2” if you have a fairly level lawn. You may want to even top dress with compost before you overseed to really kick things up.