HOW IT'S MADE
How PUTTLE builds a course every day
PUTTLE builds each day's 5-hole mini-golf course in your browser, from the calendar date. Nobody draws it that morning and no layout comes from a server, yet every player on that date gets the same holes and the same par. Play today's at https://puttle.golf.
Seeded by the date
PUTTLE turns your local calendar date into a seed. The text day:2026-10-01, with a short label added for each hole and for many features, is hashed (FNV-1a, 32 bits), and each hash starts a small random-number generator (mulberry32). Every choice the hole designer makes is a roll from one of those named streams, so a new feature can be given a stream of its own without reshuffling the rest. The same date gives the same rolls, so the same course. The day's world comes from the day number (day #1 was 1 June 2026). The date is your device's, so a new course appears at your local midnight.
How a hole is built
A PUTTLE hole is a shape, usually a headline toy, and some dressing. The shape is the turns between its legs: a straight, a dogleg, an S-bend, a horseshoe, a zigzag or a hook. The toy takes one leg — a windmill, a loop, pick-a-pipe, the Sky Cannon, or the world's own obstacle. Dressing — a planter island, a peg garden, a bunker — goes on other legs. Then come the corners, the climbs and drops, and a sculpted green with a real cup.
Each hole has a budget of things to play: two on the first two holes, three on the next two, four on the finale. So a round ramps from a friendly par-3 opener to a finale that usually has two toys. A course avoids repeating a toy, and nearly every course visits its world's signature obstacle. A hole whose fairway runs into itself, or that would play too long or too short for its place in the round, is trimmed or drawn again, up to 60 times. More: PUTTLE maps, PUTTLE hazards, PUTTLE worlds.
A robot plays every hole
Each day's PUTTLE course is robot-played under the real physics before its day comes round. The project's verifier builds the course exactly as the game does, then searches for a way to finish each hole: from the tee, and then from the most promising spots where the ball came to rest, it tries a spread of aims and powers — and, where toys move, moments to putt — through the same physics code the game runs, at 240 steps a second. A hole the robot can't finish within par + 3 fails the run. On 1 October 2026 it holed all 155 holes of dailies #123 to #153 (1 to 31 October 2026) and all 86 Sunday finales up to daily #730. That proves a hole can be finished, not that it is easy.
Where par comes from
PUTTLE's par is what a good but imperfect player shoots, measured by simulation. A second robot plays like a person: it looks at about 80 possible putts, picks the best, and hits it with error — about 2° of aim, 7% of pace, and a quarter of a second of timing at a moving toy. Its average scores on well over a thousand generated holes were fitted to a formula: a base, a price per meter of route, and a weight for each feature. Par is that estimate, rounded, from 2 to 5. From daily #134 it also takes a small correction from what real players shot.
The server keeps each day's official par and works out every score to par from it. The game posts a card only when its own par matches, so a card can't claim an easier par. Stroke rules: PUTTLE scoring.
The same course on every device
From daily #127 (Monday 5 October 2026) a PUTTLE course is identical in our tests across Chrome, Safari's engine, and x64 and arm64 processors. Sine and cosine can differ in the last binary digit from one JavaScript engine or chip to the next — far too small to see, except where the designer compared two lengths that were equal on paper. There the last digit decided, and a post or a gem could sit 10 cm or more apart in two browsers. The designer now treats lengths within a billionth of a meter as equal and breaks the tie one fixed way. Earlier dailies keep the holes they were played on: each is fingerprinted, and a check fails if a change would move one.
Designed exceptions
Not every PUTTLE hole is left to the dice. From daily #133 (Sunday 11 October 2026) each Sunday's finale is a Sunday Signature: a written recipe of three or four obstacles in a row — the world's own among them when no earlier hole has used it — laid, checked and priced by the same designer. Each night of Halloween week (25–31 October) has a written finale too. The Monthly Major's nine holes are built as of the 1st, so they never change mid-month.
Try it
- Play today's course at https://puttle.golf, then open it on a second device: the same five holes.
- Open the Frostpeak practice course with the seed frost-7: the seed is in the link, so everyone who follows it gets the same course.
- Give the designer a recipe of your own in the Hole Builder: it lays a real hole and prices its par, or says it won't fit.
The short version: How is today's PUTTLE course generated?
Updated
Play today’s course