The number of possible chess moves has been estimated to be even more than the number of atoms in the universe. The number of atoms in the universe is thought to be as many as 10^{81}, or 10 multiplied by itself 81 times, while the number of possible moves in chess is estimated to be 10^{120}. This calculation for chess movements is known as the Shannon number. The Shannon number includes illegal chess movements and is named after American mathematician Claude Shannon, who calculated this estimation in 1950.

**More about chess**:

- The first chessboard with alternating light and dark squares is thought to date to 1090 A.D. in Europe.
- The smallest possible number of chess moves in a complete game is two for each player. A two-move checkmate is often referred to as a "Foolâ€™s mate" because it typically occurs only against very inexperienced or weak opponents.
- Chess games are estimated to consist of 30 moves on average, and any game beyond 60 moves is considered very rare.

## Discussion Comments

Yeah, there's a Novemtrigintillion of possible chess moves, 10^120 that is.

If one were to "solve" chess as a computer, mathematically you'd have to systematically go through very possible move, subtract the moves already taken, and take the logical move. Chess is easy for computers to understand because it's a zero-sum game with no chance for "luck" or rather, non-mathematical factors to take place. (i.e. the queen can't just turn black because you're not a good ruler.)

A human can't logically go through all that.

There are 43,768 moves for white and black. Not all are possible at all times; there are only 20 possible moves at first. The combinations of moves would take "forever" to count - any count is a gross estimation.

Ten to the Eighty-first Power = 8,100

Ten to the One hundred twentieth power = 12,000.

These are not brobdignagian numbers, as one might use in quantification of all matter in the universe. Can anyone elaborate?

Awesome post! Who knew there were so many moves?

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