Memory Match

How to play

Every card has a twin somewhere on the board. Flip one, flip a second, and if the two symbols agree the pair stays face up for good, dimmed so you can see at a glance what is settled. If they disagree they stay visible for a moment — long enough to actually register where they were — and then turn back over while the board is briefly locked, so a fast second click cannot skip past the information you were meant to collect.

Three sizes are on offer: 6 pairs on a small four-column board, 8 pairs as the standard four-by-four, and 12 pairs across six columns for a real test. The size you last chose is remembered, and each keeps its own best move count and best time.

The symbols themselves are plain text characters — a star, a heart, a diamond, a couple of Greek letters and so on — rather than pictures. That is a deliberate choice: nothing has to be downloaded, the board looks the same on every device, and no card ever renders as an empty square because a font is missing. Twelve symbols exist in total and each deal shuffles them before taking however many the board needs, so a six-pair game draws a different half of the set each time you press Deal again.

Controls

• Mouse or touch — tap any face-down card to flip it. Cards already matched, and the card you just turned over, do not respond.
• Keyboard — every card is a genuine button, so Tab and Shift + Tab step through them in reading order and Enter or Space flips the one in focus.
• Screen readers hear the position of each card and, once it is face up, the name of its symbol and whether it has been matched.
• Moves counts turns, not clicks: it rises by one when the second card of a pair is revealed. Pairs shows how many of the set you have found, and the clock starts on your first flip rather than on page load.
• Deal again reshuffles both the symbols and their positions.

The rule that turns luck into method

Concentration looks like a game of pure recall, and it is not. There is a decision inside every turn, and getting it right is worth more than any feat of memory: which card do you flip second?

Start with the first flip. It should almost always be a card you have never seen, because the whole point of the turn is to learn something. Turning over two cards you already know, purely to collect a pair you had spotted three turns ago, is a legitimate move and it costs you exactly one move on the counter — but it teaches you nothing, so save it for the point where you have nothing better to do.

Now the interesting half. You have flipped an unknown card and it shows a diamond. If you already know where the other diamond is, flip that card and bank the pair. If you do not, you have a genuine choice: flip another unknown card and learn a second fact, or flip a card you already know and learn nothing. Always take the second unknown. The pair might match by luck, and even when it does not you now have two new locations in your head instead of one. Over an eight-pair board that difference is typically several moves, which is exactly the range the Best moves counter lives in.

The corollary is a habit worth building deliberately: when a turn fails, do not look away in frustration. The two cards are still face up for a moment, and that moment is the entire reward for the move you just spent. Players who finish in the mid-teens on the eight-pair board are not remembering more than everybody else; they are simply choosing to look.

Storing positions instead of cards

Most people try to remember the cards — "the heart was over there somewhere" — and the vague spatial memory decays within two turns. What survives much longer is a position with a label attached, so give each card an address before you try to store it. Row two, third along, is a heart. Bottom left corner is omega. The grid is small enough that a coordinate is easy to say to yourself, and something you can say is something you can rehearse.

On the six and eight pair boards that is usually enough on its own. The twelve-pair board is where it breaks down, because nobody holds twenty-four independent facts. The technique that scales is chunking: stop tracking cards and start tracking rows. Rather than six separate items, the top row becomes one thing — "top row: star, spade, blank, blank, circle, blank" — and you rehearse the row as a unit whenever you flip anything in it. Four chunks of six beat twenty-four singletons, and the pairs you complete take their cards out of the chunk, so the load falls as you go instead of rising.

Where the game came from

This is one of the oldest games that needs no equipment beyond an ordinary deck of playing cards: shuffle, lay every card face down in a grid, and take turns flipping two. It is known in English as Concentration, as Pairs, and in Britain often as Pelmanism, a name borrowed from the memory-training courses that were widely advertised in the early twentieth century.

It reached a much bigger audience as a television format. Concentration began on NBC in 1958 and ran, in one incarnation or another, for decades, pairing the matching game with a rebus puzzle revealed piece by piece behind the cards. The version on this page keeps the matching half and leaves the rebus alone; the code and the wording here are our own, written for this site.

Questions players ask