A
Andrew Albright
Guest
So everyone knows that Lance Armstrong is trying to win his 5th Tour of France in a row.
In a recent article in the Inqy, Armstrong said, "The mathematics get tricky with any streak. The
odds will tell you the chances decrease the more you go along". [The author of the article, Bob
Ford, compounds the error with his analysis of Armstrong as being a person who can 'crunch numbers
with anyone'].
Most of you reading this probably aren't all that smart, so let's pretend that we aren't talking
about Tour of France wins, but rather flipping a coin and trying to get a streak of 'heads' going.
The chance of flipping a coin four times in a row and getting heads all four times is 1 in 16, less
than 10%; the chance of getting 5 heads in a row is 1 in 32.
However, if someone has flipped a coin and already has flipped four heads in a row, the chance of
getting a head when he flips the coin the fifth time is 1 in 2.
It is basic probability theory that each test (flip of the coin) is indepedent of previous tests.
Now I know that this is probably over the heads of most of you, but I thought that I would try to
educate you all anyway.
In a recent article in the Inqy, Armstrong said, "The mathematics get tricky with any streak. The
odds will tell you the chances decrease the more you go along". [The author of the article, Bob
Ford, compounds the error with his analysis of Armstrong as being a person who can 'crunch numbers
with anyone'].
Most of you reading this probably aren't all that smart, so let's pretend that we aren't talking
about Tour of France wins, but rather flipping a coin and trying to get a streak of 'heads' going.
The chance of flipping a coin four times in a row and getting heads all four times is 1 in 16, less
than 10%; the chance of getting 5 heads in a row is 1 in 32.
However, if someone has flipped a coin and already has flipped four heads in a row, the chance of
getting a head when he flips the coin the fifth time is 1 in 2.
It is basic probability theory that each test (flip of the coin) is indepedent of previous tests.
Now I know that this is probably over the heads of most of you, but I thought that I would try to
educate you all anyway.