He has drawn the same imaginary city for 60 years and lets a deck of cards decide what to paint

A map that has outlived the artist's own choices

In the summer of 1963, Jerry Gretzinger started doodling a city map to pass spare time at work. He kept at it until 1983, then dropped it for two decades; his son found it in the attic of their Cold Spring, New York home and Jerry picked it back up. The result, documented at jerrysmap.com, is over 4,000 individual 8-by-10-inch panels that assemble into a rough circle, each panel addressed by N/S/E/W coordinates from the center.

The engine of the whole thing is a deck of roughly 100 cards that functions as a random-number generator. Each card carries a number (the count of one-inch squares to work) and a color that sets direction — black clockwise, red counter-clockwise. The cards don't just say where; they say what: paint a panel, spatter, plant a new "seed" of growth, do collage or screen-printing, build blank panels from recycled material and lumen prints — and sometimes the card tells Jerry to modify the deck itself, retiring a card or reshuffling. New work never paints over an original; it spawns a new version of the panel, and when panels fill up the map grows outward to keep its circle.

Gretzinger frames himself not as the author but as a witness: "There's a reality in there waiting to get out," and he is "merely the observer."

The thread: a system to observe, not a drawing to finish

The comments treated it less as art and more as a six-decade running simulation, and converged on one eerie consequence. Working a single tile at a time, Jerry rarely sees the whole:

"He seemingly only gets to see what it actually looks like at intervals like 15 years apart. There are probably entire epochs of his system that he'll never actually see laid out because they've since been overridden." — a commenter on the overwritten epochs

What readers admired wasn't the randomness but the line it draws around it. The deck decides the moves; the brushwork stays human:

"his system pushes the creative process forward without relinquishing the actual creative part of it (making the map tile)." — a commenter on where the deck stops and Jerry starts

It also pulled stories out of people who'd done a smaller version of the same thing. One described platting subdivisions into hand-drawn coastlines as a kid and calling it "delightfully meditative"; another remembered entering 16x16 map grids into a computer one tile at a time and printing them on an Epson MX-80 dot-matrix, making sure the edges matched. — a commenter who tiled maps on an Epson MX-80

The project lands squarely in the outsider-art tradition one reader invoked — the Henry Darger lineage of private worlds built to their own rules — and the obligatory verdict arrived early and stuck: "The most Borgesian thing to ever be posted on HN." The reason it resonates on a programmer forum is that Jerry built, by hand and on paper, the thing a lot of people quietly want: a generative system you tend rather than control, where the rules outrank the author and the output keeps surprising the person making it.