I agree with Gadget.
I personally think if you have ancestors from countries that had a high emigration rate to the US you will have far more matches, as America obviously has the most people in this world that has taken the DNA tests.
By far the most matches I have is from my mother's sides ( my mum is Irish) , where my paternal sides didn't emigrate to the same high extent that my mother's sides did( father is Welsh) . My own Irish families did not have any more children than my Welsh families did , I think my welsh lot had more children, without counting them all.
My paternal side accounts for only 7000 DNA matches, whilst maternal is over 19000 DNA matches ( minus my close family such as 1st , 2nd and some third cousins , the rest are just
countless Americans in that 19000 from my maternal side )
I know many of my mum's lot migrated to America, where only a few of my father's lot did. I have quite a few known ones in the US
A few on my father's side emigrated to Pennsylvania with the coal , but not many, I can literally count on one hand that the ones that emigrated to the US from my dad's side, where I can't count off hand with my mother's sides, it would take me a good while to look through my tree and count all of the ones that emigrated there, there are heaps of them .
Mine says I have 793 4th or closer ,which considering above, the huge difference between my maternal and paternal figures , 19000 compared to 7000, the majority within that 793 figure will be from my mother's sides and not my father's sides.
My guess is if I had two Irish parents, and not one, my figure would be over 1000 , or if I had two Welsh parents instead of the one, my figure would be lot less than that 793 .
It's the same with my child's DNA too, he has over double the amount of matches on his maternal side ( me) than his father's / my hubby sides ( hubby is basically 100% welsh minus his Finnish gg grandfather )
Kind regards