In the last 17 years I've planted around 4500 oaks on property I own. Last year was the first year that any of the trees I'd planted produced any acorns. Man, did they ever produce acorns! I had tens of thousands of them. Anyway, in late spring I noticed in clear paths where some new seedlings were growing. It seemed that they were growing best where my lawn mower had pressed them into the ground. On closer inspection, some of the acorn was still visible at ground level, but most of the acorn had been pressed into the soil by the turf tires.
I have no idea if that proves anything at all. It is just my observations. Well, I guess it does prove one thing. I'd always heard that oaks do not produce acorns until they are 50 years old. I'll step out on a limb and say that I can at least say that is false. Around their 15th year, it seemes like most of my oaks began producing acorns. Good luck! I think oaks are fantastic trees.