brett's posterous

A Chart for Two Letter Words!

Since I began playing Scrabble as a child it has been clear that knowing the two letter words is vital to game strategy. And while I've seen lists of the two letter words before I've always wanted the list organized in a specific way, namely, laid out by letter with all the words that start and end with that letter. I don't know if at some point I saw this somewhere or if it's just been something in my head. Either way I couldn't find the letters charted the way I wanted so I took it as a good opportunity to mess around with Rapahel.js. Meet two letter word chart. I made sure it formats pretty well on iOS devices (and used mobile Safari's web app feature so you can "Add to Home Screen" to make the site act like an app without the Safari chrome). 
Oh and I've been playing a lot of Words With Friends with my Grandma so it you can switch to WWF's (mystifyingly different) two letter word list as well. 

"Quad is quad."

If the Olympic champion doesn’t know how to jump quad, I don’t know,” a dispirited Plushenko said. “Now it’s not figure skating. Now it’s dancing.
via nytimes.com

I don't follow figure skating and I don't care much what happens. But I do know that when I hear the 2nd place finisher accuse the winner of "dancing" instead of figure skating that's really hilarious.

Good Explanation of Why Medical Probabilties are Often Counterintuitive

Assume there is a screening test for a certain cancer that is 95 percent accurate; that is, if someone has the cancer, the test will be positive 95 percent of the time. Let’s also assume that if someone doesn’t have the cancer, the test will be positive just 1 percent of the time. Assume further that 0.5 percent — one out of 200 people — actually have this type of cancer. Now imagine that you’ve taken the test and that your doctor somberly intones that you’ve tested positive. Does this mean you’re likely to have the cancer? Surprisingly, the answer is no.

To see why, let’s suppose 100,000 screenings for this cancer are conducted. Of these, how many are positive? On average, 500 of these 100,000 people (0.5 percent of 100,000) will have cancer, and so, since 95 percent of these 500 people will test positive, we will have, on average, 475 positive tests (.95 x 500). Of the 99,500 people without cancer, 1 percent will test positive for a total of 995 false-positive tests (.01 x 99,500 = 995). Thus of the total of 1,470 positive tests (995 + 475 = 1,470), most of them (995) will be false positives, and so the probability of having this cancer given that you tested positive for it is only 475/1,470, or about 32 percent! This is to be contrasted with the probability that you will test positive given that you have the cancer, which by assumption is 95 percent.

via nytimes.com

The whole article about how this relates to "the recent brouhaha over the guidelines put forth by the government task force on breast-cancer screening" is well worth reading.

SF 1 Bedroom rents over time

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Pretty interesting. Some dude scrapes Craigslist for rent prices and outputs a bunch of interesting maps and graphs. See more here.

I knew our rent was low, but I didn't realize how low. I guess we're never moving. In related news I was looking at condo prices in my neighborhood. They're actually getting low enough that I think 30 year fixed mortgage payments on a 2 bedroom are closing in on parity with rent prices.