Wednesday, July 23, 2008

Matching birthdays

Today we illustrated a famous problem in probability called the birthday problem. Suppose you look at the active roster of a Major League team -- what's the chance that at least two people will have matching birthdays (month and day)? The answer is surprisingly high -- over 50%. Since I wasn't sure if you believed this, I had each of you find the active roster for one MLB team. Thirteen of us found rosters, and in 9 of these rosters, we found a matching birthday. So

Prob(match) is approximately 9/13.

We also talked about several more sophisticated baseball simulation games. You will be making spinners for the All-Star Baseball game. Here each batter is assumed to have a different ability and the chances that he will get a walk, out, single, etc are represented by slices of the spinner. A more sophisticated game Strat-O-Matic is based on the use of player cards (both batters and pitchers) and three dice. Strat-O-Matic actually is a very realistic game in that the games resemble actual baseball games.

We'll be covering Chapter 5, Probability distributions, tomorrow.

The Phillies had a great victory over the Mets last night -- hopefully Bret Myers will come through for the Phils tonight.

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