PQ is a measure of your ability to predict future events, expressed as the strength of your deviation from the success of random guesses, and normalized to a number between 0 and 1000. Those of you who could decode that sentence realize that this measure will give you a perfect score of 1000 if you guess a coin flip correctly 100% of the time, or if you get it wrong 100% of the time (which, if you think about it, is just as difficult).
The tester below was created in Director format, and originally had a high score mechanism which I have had to remove to make the code available on the web. That creates a few minor quirks in the way the screen behaves. Enjoy.