Archive for July, 2007

Bookie Math

Tuesday, July 31st, 2007

In a best of 5 series, you want to bet $100 that team A will win, but your bookie will only take bets on individual games. (The bookie pays even money on all bets.)

The question is, how do you figure out how much to bet on each round? In fact, figure out how to bet for every best-of-N game.

The original quiz is located here:

Solution, in Python:
Solution, in Common Lisp:

Scores Bet
0 0 37.5
1 0 37.5
1 1 50.0
2 0 25.0
2 1 50.0
2 2 100.

Saw it at

Pass right through

Monday, July 2nd, 2007


I’ve seen doors quite a few times in my life. Certain doors, especially the ones without locks, I pass through often, and almost forget about. There is a second type of forgotten door, the ones that I wish did not exist. These latter doors have their destination painted on in huge bold letters, always in the same font. Below the huge letters of that font, in very tiny print, is the warning:

“entrance only. return impossible.”

Nth order work

Monday, July 2nd, 2007

I have a few pet peeves, and the one that gets me into the most trouble would be my refusal to do any zeroth order work. Zeroth order work is work that when done now saves one exactly the same amount of effort as when it is done later. It is the merest type of work, work with a zero interest rate, work that doesn’t reflect any form of investment. Granted, work of the purely zeroth order type is not easy to find – even doing the laundry makes one more proficient at doing laundry, after all. However, amongst the different tasks available, there are just some that are so blatantly close to zeroth order that I cannot bear to do them. These are the tasks that, as I do them, I feel the clock of mortality ticking away, and I feel guilt at having wasted another second, minute or hour of my biological life while the mental clock was stopped.

High order activity, on the other hand, is a delight. It is usually hard to determine exactly how many orders up a particular activity is, but I’ve always looked to philosophy as ultra-long-term investment, fruitful activity that may take a while, but inevitably trickled down into one’s life in a myriad of ways, enriching many branches with subtle, strengthening transformations.


Sunday, July 1st, 2007

I need help understanding this paragraph from The Economist:

His grim prediction is based on the “impossible trinity”: an economy cannot control domestic liquidity and manage its exchange rate if its capital account is open. If it holds down its currency, foreign-exchange inflows will boost money growth. The central bank can try to “sterilise” the impact of bigger reserves by selling securities to mop up the excess liquidity. The snag is that bond sales will tend to push up interest rates and so attract yet more capital inflows. Mr Roubini believes that the room for sterilisation by Asian central banks is severely limited and so rising reserves mean even greater excess liquidity.