Infinite Search Space logo: an infinity symbol infinitesearchspace.com
Poster: two glowing stone arches rise from a lake at night, the top half of an infinity symbol, and their reflection in the rippling water completes it. A lone explorer with a lantern stands on a stone jetty, between orchards and fields of coloured puzzle tiles. Title: Infinite Search Space, the search continues. Returning soon

Back after thirteen years.

Infinite Search Space hosted recreational maths and programming contests in 2011 and 2012: hard puzzles that ran for months, were scored to the last digit, and were played mostly for bragging rights. It's coming back, with new contests, and a classic room where the old records can finally be beaten.

On two occasions I have been asked, “Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?” … I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question.

— Charles Babbage, Passages from the Life of a Philosopher (1864)
In good company

Two contest sites that shaped ISS

Al Zimmermann's Programming Contests

azspcs.com

For many of us, Al Zimmermann's contests are the gold standard: one beautiful problem, months to chip away at it, a leaderboard that counts every improvement, and results that still turn up in the OEIS. ISS was built in their image. Its founder learned the craft on Al's problems, finishing 10th in Retaining Water. ISS's very first About page thanked Al, and it still does.

Virtual Source Programming Contests

v-sonline.com

James J. Youlton Jr's contest site, home to Primal Rings, Tribal Primes, Pyramid Power, King Walking, God's Dice and more. ISS's founder entered every one and helped James put the contests together, and the two sites have always cheered each other on. James is a friend, and a big part of why ISS exists.

The first time around

Four contests, players from all over the world

Orchard Planting

Sep – Dec 2011

Plant N trees on whole-number points to make as many rows of exactly four as possible.

WinnerIl Brigante Pennastorta

SameGame

Jan – Apr 2012

Clear 25 boards of coloured tiles for the highest possible score.

WinnerWes Sampson

Monochromatic Squares

May – Aug 2012

Colour the largest grid you can, with up to 21 colours, so no rectangle has four corners alike.

WinnerAlex Chernov

Prime Sums

Late 2012

A prime-number puzzle that ended in a dead heat at the top.

Joint winnersDmitry Kamenetsky & Alex Chernov

Still remembered

Where the contests left a mark