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# A mind reading experiment (continued)

I think you are thinking of the word 'four' !

## Magic?

No - maths ! This effect is called the Kruskal count, named after the mathematician Martin Kruskal, who discovered it in the 1970's. His research showed that seemingly unconnected or unrelated chains of events could join up and lock together after a while. When the total number of letters in a text is much larger than the number of letters in the longest word, it is likely that word chains started some place at the beginning of the text will at some point intersect at a keyword. After that point, of course, the chains must become identical. As the text gets longer the likelihood of this 'magical' coincidence increases. Seems a little weird, but that's what the maths says, and it works most of the time with the right kind of text, so why not try an experiment on your favourite book and amaze your friends.

## Further reading for the very brave

The Kruskal Count is often used as a prediction card trick. Maybe you can invent your own trick based on it? If you are brave enough you can even read a scientific paper about why the trick works. It's not for the mathematically faint hearted, as it contains some fairly hairy maths, but it does show that the magic is in the maths.