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Consider the following.

Imagine two rooms.

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Inside each room is a switch.

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In one room, there is a man
who flips his switch according

to a coin flip.

If he lands heads,
the switch is on.

If he lands tails,
the switch is off.

In the other room, a
woman switches her light

based on a blind guess.

She tries to simulate
randomness without a coin.

Then we start a clock, and they
make their switches in unison.

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Can you determine
which light bulb

is being switched
by a coin flip?

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The answer is yes, but how?

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And the trick is to think about
properties of each sequence

rather than looking for
any specific patterns.

For example, first,
we may try to count

the number of 1's and 0's
which occur in each sequence.

This is close, but
not enough since they

will both seem fairly even.

The answer is to count sequences
of numbers, such as runs

of three consecutive switches.

A true random sequence
will be equally

likely to contain every
sequence of any length.

This is called the
frequency stability property

and is demonstrated
by this uniform graph.

The forgery is now obvious.

Humans favor certain sequences
when they make guesses,

resulting in uneven patterns
such as we see here.

One reason this
happens is because we

make the mistake of
thinking certain outcomes

are less random than others.

But realize, there is no
such thing as a lucky number.

There is no such thing
as a lucky sequence.

If we flip a coin
10 times, it is

equally likely to come
up all heads, all tails,

or any other sequence
you can think of.

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