Bradbury handed out a lot of advice over a long career, but one line keeps getting quoted because it's so easy to test. Write a story a week, and the math eventually rescues you.

The Direct Answer
Write one short story every week.
His logic was that it's not possible to write 52 bad stories in a row, a line from his 2001 keynote at Point Loma Nazarene University's Writer's Symposium by the Sea.

The 52-Story Rule

The weight of a novel can freeze a beginner solid. A short story can't, because there's always next week. Bradbury's whole pitch was that quality isn't your job at the start. Frequency is. Keep finishing stories, week after week, and somewhere in the back half of the year a good one shows up almost by accident. He'd watched it happen to himself, and he promised it would happen to you. The trick was to stop protecting your ego and start filling the wastebasket.

He delivered the line in 2001 at the Writer's Symposium by the Sea, in a talk he called Telling the Truth. The full version of the thought was generous and specific. Write one story a week, never mind the quality to start, and at the end of the year you'll have 52 of them, and he defied anyone to write 52 bad stories in a row. It works because finishing is a skill, and you only build it by finishing things, over and over, until the ending stops scaring you.

The rule also quietly solves the beginner's biggest trap, which is endless revision of a single piece. Polish one story forever and you learn one story. Finish 52 and you learn structure, voice, openings, endings, and how to cut your losses on the ones that won't come together. Bradbury wasn't promising that every week would produce gold. He was promising that the odds bend in your favor once you stop waiting for inspiration and start keeping a schedule.

Write a short story every week. It's not possible to write 52 bad short stories in a row.

Ray Bradbury, Writer's Symposium by the Sea, 2001

Write With Zest, Feed on Libraries

Two other themes run underneath that rule across all his talks and essays. The first is feeling. Write with heat or don't bother, he argued in Zen in the Art of Writing: if you're writing without zest, without gusto, without love, without fun, you're only half a writer. The cold drafts are the ones that bore everyone, including the person typing them.

The second is appetite. Bradbury credited libraries over any university for making him a writer, and he urged people to feed on books, to read poetry every day, to stuff themselves with essays and short stories until ideas started colliding on their own. That's not a side note for him. It's the fuel that makes a story a week even possible, because you can't pour from an empty cup and you can't write 52 stories on a starved imagination.

Put the three together and you get a working system, not just a slogan. Read constantly to load the tank. Write with zest so the work stays alive on the page. And finish a story every week so the calendar does the heavy lifting your willpower can't. None of it is mysterious, which is exactly why it has lasted. For the daily habits behind the advice, see the full Ray Bradbury writing routine.

What You Can Steal