Thursday 4 September 2008

Life, Risk and Probability


Who likes the risk game?, Who plays the risk game?
OK, for those of you who don't know it, simply stated it's the world conquest game.
It's just a board game before someone comes around and accuses me of trying to take over the world.
In the better days me and my friends would gather and play all night long, all six of us.
I would light up a nice big Cuban cigar, and play with my huge 17th century "sawalef" that i once had.
"Let's go General" they would say, and the game would start.
Basically each has his own army which is deployed around the world, and when a battle is underway a roll of the dice decides the fate of your armies.

The system goes like this:

For offense : Attacking with one battalion the player gets to use one die
Attacking with two battalions you get two dice
Attacking with three or more battalions you get 3 dice

For defense : Defending with 2 or less battalions - one die
Defending with 3 or more battalions - Two dice.

It's game of wits, and the enrolling of dice in the game makes it dependent on luck, much like real life.
It was something, contrary to life though, that i excelled at.
Close to the completion of my mission and the winning of the game, i had only one territory to occupy.
A territory(japan i believe) occupied by B., who was by then in a weak position with only a few battalions left intact. In fact he had only one battalion to defend that territory.
I attacked with 3 battalions, a number which i thought sufficient to crush his one battalion defense.
This means that i was throwing three dice and he was throwing only 1.

1st round - The probability that he would win this round is the following:

1/4 * 1/3 * 1/2 = 1/24 = 0.0416 = 4.16%

The probability that i win is therefor: 95.84%

You can guess where all this is going, he DID win the round, surviving somehow on the tiny 4%.
But there is more to the story, after my loss i had to wait another round to try to occupy the territory.

2nd Round - I begun suspecting that lady luck might not be on my side, so i increased the no. of attacking troops to 6 battalions.
The probability that he would win:

1/4 * 1/4 * 1/4 * 1/4 * 1/3 * 1/2 = 1/1536 = 0.00065104 = 0.064104%

and taking the probability of the first round into account, the probability that he would win BOTH rounds is:

0.00065104 * 0.0416 = 0.000027082 = 0.0027082%


.'. The probability that i would win: 99.9972918%


And yet again he won and i lost....... blowing my 99.99% into oblivion with his 0.0027%.

3rd round
- I yet attacked with 6 battalions, being all i had left near the battle ground.
The probability that he would win:

0.00065104

taking the 1st and 2nd rounds into account, the probability that he would win ALL three rounds:

0.00065104 * 0.00065104 * 0.0416 = 0.0000000176605 = 0.00000176605%

which means that he had 17.66 in a billion chance to win, and he did!

The probability that i would win: 99.99999824%

which by any reasonable approximation would amount to 100%
Probability says that i would win, 100% sure i would, but i lost....

Through the exuberant cries of B., the disbelieve so generously drawn on the faces and the puzzled lump of my psyche, i thought about probability and how dangerous it really is.
Just a virtual aspect of it all, life clearly does not believe in it.
Who would put faith in something so deceiving??

3 comments:

Sou said...

oh my god risk i suddenly feel old?? U brought back memories
I really like the description on the side some one is there but they are simply not answering :)

Queen O'Danile said...

Hey Vile! Followed your comment left on my blog and though I didnt spend much time here this morning, I will come back. I'm gonna like your blog...I can tell already. Talk to you soon!

Vile said...

I'm currently saving a Cuban, just in case....
assuming someone's around, it's an alternative nobody thinks about.

Queen : make yourself at home.