Every day. Growning up, friends and I would play games in our yards all the time. "Back in the day" we'd play neighborhood wide games of hide and seek, running across neighbors yards (who didn't have kids, but didn't mind) and everything. We routinely played baseball, football and soccer too.
Everyone's desire for a big yard means such gatherings can be pretty rare because there aren't many kids to gather with. Not clear to me why somebody's house is going to be better than a park anyway.
I grew up in a house with a double lot, and the neighborhood kids would come around. It was the baby boom, so even in a suburb there were lots of kids. We would play tag, hide-and-go-seek, kickball, whiffle ball, touch football, mother-may-I, and who knows what else I've forgotten.
> how often did you do that in your yard as a kid?