July 13, 2020:
Marbles are for keeps.
We play all over the field, something like golf on an endless open course where the goal is not to land your marble in a distant cup but to hit the other fellow's marble without him hitting yours. Hit the other marble and you own it. Our goal is a huge and varied collection, particularly the prized pureies and steelies.
These contests are boys only. Girls neither play nor watch. It's two boys, always one-against-one, a duel beneath eucalyptus, over roots and behind rocks, like a dogfight in two dimensions where the contestants politely take turns but their purpose is ownership.
Game theory: there are advantages to going first or second. If first: how far to shoot, to make it hard to be hit, yet give yourself a chance to come back when it's your turn. If second: whether to try for an immediate hit, or cover only part of the distance, forcing the other fellow to return toward you; or try something else entirely. Either way you maneuver to site your marble at a distance and over a terrain where you're confident you can hit the other with your next shot without him being able to hit you with his. I can win playing first or second: I can reliably hit from many yards away over broken, sandy ground.
There's never a formal hierarchy of victors. If there were, I'd be at or near the top. I began with a small mixed bag my mother bought me for starters: ten cents or something from the local five-and-dime. By the time we move away I have half a dozen two-pound coffee cans full of the things. Since kids in our new neighborhood don't play marbles I shoot them into the canyon with a slingshot, one at a time. It requires several days.
The anthropology is interesting, although at the time of course I lack the vocabulary to say that out loud. The cultures of the two schools are so different. In La Mesa we loved marbles and antlions. In Clairemont no kid's heard of antlions and they seem to believe marbles are for display not for combat. After grammar school at Rolando I never meet another marble player, ever.
Our rules seem unusual as well. I've seen cartoons of kids in groups playing marbles inside a circle drawn on the ground. There'll be some number of marbles all scattered close together inside this constrained space. I wouldn't know how to do that. It's not what we do. We play all over the schoolyard. Always one against one.
Kids would show off their prizes. Single-color glass "pure-ies", very rare. Or all-metal "steel-ies", like miniature ball bearings, where the larger "boulders" were more desirable. We'd ooh and ah as friends opened their hands to display some stunning new acquisition. I vividly remember winning my first steelie boulder: how happy I was, and how dejected the other kid was to have to give his up.
I never saw anyone selling marbles. We won them, or bought new ones from the five-and-dime. I have no idea where the pure-ies or especially steel-ies came from. Only that by the time we were done they were mostly all mine.
It's interesting also that for the most part the boys didn't know one another. We were from different classes, all different ages. If we wanted to play we met near the schoolyard fence under the swaying eucalyptus. In time I knew several boys by sight, but I now remember nobody's names, and I doubt that at the time I ever asked. This wasn't about friendship. It was serious business.