Where Tetris Came From and Why Its Seven Pieces Work

Ask a room of people where Tetris came from and you will hear a surprising range of answers. Japan, because of the Game Boy. America, because of the arcade machines. Someone usually remembers "Russia," but few can say much past that. And almost nobody can explain why the game uses exactly seven shapes, not six or twelve, even though that number is the whole reason it works.

Both questions have clear answers, and they connect. The pieces came out of a mathematical puzzle, the number seven is not a design choice so much as a fact of geometry, and the strange route the game took from a Moscow research lab to nearly every screen on earth explains why its creator earned nothing from it for over a decade.

A puzzle from a research lab

Tetris was written in June 1984 by Alexey Pajitnov, a researcher at the Dorodnitsyn Computing Centre of the Soviet Academy of Sciences in Moscow. He was not working on games. His job involved artificial intelligence and speech recognition, and he wrote small programs on the side to test new computers.

The machine he used was an Electronika 60, a Soviet computer with no graphics at all. The first Tetris pieces were drawn with text characters, square brackets standing in for blocks. There was no color and no music. What there was, from the start, was the core idea: shapes fall, you rotate and place them, and full rows disappear.

The name combines two words. "Tetra," the Greek prefix for four, because each piece is made of four squares. And "tennis," Pajitnov's favorite sport. That second half is a detail people rarely believe until they look it up.

Why seven pieces, exactly

Pajitnov loved a puzzle called pentominoes: flat shapes made by joining five squares edge to edge. There are 12 distinct pentominoes, and fitting them into a rectangle is a classic brain teaser. His first idea was a game built on them.

Twelve shapes turned out to be too many for a real-time game. Players could not learn them fast enough, and many pentominoes are awkward to fit. So he dropped down to four squares, and that is where the magic number appears. If you join four squares edge to edge in every possible way, and you count mirror images as different (because in Tetris you can rotate a piece but cannot flip it over), you get exactly seven shapes. Not a designer's choice, but every possibility there is.

Players have given them letter names based on what they look like:

Seven turns out to be a sweet spot. It is few enough that a new player learns every piece within a game or two, and enough that the next one is never quite predictable. The S and Z pieces matter more than people think: they are the reason a stack gets messy, and a game with only the friendly shapes would be far too easy.

Clearing four lines at once is itself called a "Tetris," and only the I piece can do it. That is why experienced players leave a single empty column on one side of the stack and wait. It is a deliberate gamble on the I piece showing up in time.

How modern versions keep it fair

In early versions, pieces came at random, which meant you could go a very long time without an I piece. Most official versions since the early 2000s use what is often called a "bag" system: the game shuffles all seven pieces, deals them out, then shuffles again. You will see every shape once in every seven. The longest you can ever wait for an I piece is twelve pieces, which is the case of one arriving first in one bag and last in the next.

From Moscow to the Game Boy

Here is the part that makes the history famous. Tetris spread around Moscow on floppy disks, and a younger colleague, Vadim Gerasimov, ported it to the IBM PC. Copies found their way to Hungary and then to the West. Because the Soviet Union had a state agency, Elorg, that controlled the rights to software made in its institutes, Pajitnov did not own his game. Several Western companies ended up believing they held rights that overlapped or contradicted each other.

The person who untangled it was Henk Rogers, a Dutch-born game publisher based in Japan, who flew to Moscow in 1989 and secured the handheld rights for Nintendo. Tetris shipped bundled with the Game Boy, and that version alone sold around 35 million copies. The music most people hum when they think of Tetris is a 19th-century Russian folk song called "Korobeiniki," arranged for the Game Boy's sound chip.

Pajitnov received no royalties during this period. That changed only in 1996, when he and Rogers founded The Tetris Company to manage the license. The two remained close friends, and the whole tangled story was dramatized in a 2023 film simply titled Tetris.

A game still giving up its secrets

You might think a puzzle this old would be fully solved. It was not. In December 2023, a 13-year-old from Oklahoma named Willis Gibson became the first person known to reach the point where the original 1989 Nintendo version crashes, at level 157. Players had assumed for decades that the game simply went on forever. Getting there required a rapid-tapping technique called "rolling," developed by the competitive community only a few years earlier.

There is also a name for what happens when you play too long. The "Tetris effect" describes seeing falling blocks when you close your eyes, or mentally fitting real objects together, like groceries or suitcases in a car boot. The term was popularized in a 1994 magazine article, and it has since been used by researchers to describe how any repeated activity can shape what the mind notices.

If this sort of background interests you, our piece on why remakes and remasters matter picks up a similar thread about old games finding new audiences, and how video games became a mainstream hobby covers the wider story Tetris helped kick off.

A small thing to try this week: play one game of any Tetris version and keep an empty column on the right side the whole time, saving it for an I piece. Count how many four-line clears you manage. It is the fastest way to feel why seven pieces, and specifically that one long one, make the whole thing tick.