Tag Archive: The Law of Large Numbers


(Story submitted by reader David Buck)

I work on contract in the software development field and I specialize in Smalltalk programming – a relatively obscure programming language these days.  I normally have a full time contract but one day, my project leader told me that there would be a gap in the contract and it might be several weeks or months before they could get me back in.

I went into “find work” mode and thought about companies I’d done business with in the past.  I decided that I’d contact one insurance company first. I hadn’t heard from them since Nov 18, 2003 (some five years earlier).  The last I heard, they needed to do an upgrade and I thought that if they hadn’t done it yet, I might be able to help them out.

I frequently do this work under a subcontract for the Smalltalk vendor, so I decided to email my contact there – a fellow named Jim. On the morning of January 28, 2010, I emailed Jim to suggest that we contact the insurance company to see if they needed any work done.  I mentioned that I last heard from them in 2003.  Jim agrees and asks me to send him the email address of the contact person.  I don’t have that email address on my smart phone so I tell Jim that I’ll send it to him after I get home a few hours later.

Well, less than a few hours later (before I got home), I got an email out of the blue from the senior manager of the insurance company.  He wanted to know whether I still did that kind of work and whether I was available to do the upgrade work for them.  At no point did Jim or I communicate with them about this work.  They just sent the request on their own on the very day that we were planning to contact them.  I forwarded it to Jim and we started contract negotiations.

I ended up getting a contract with them for six months and successfully completed the upgrade for them.

So, what are the odds that in the three or four hours between Jim and I agreeing to email them and actually emailing them that they would email me instead after five years of no contact?  Weird.  The Law of Large Numbers works in mysterious ways.


Below are the extended notes provided by Barbara Drescher for use in Skepticality Episode 192. Take a look and leave your comments below.

First, I have to question the reliability of the timing this author outlines, because his (assuming the author is male) numbers don’t add up. The timing is not particularly relevant, but it does demonstrate a possible fallibility of memory or documentation.

Setting that aside, it sounds a lot more unusual than it is. The author not only knew the manager and had worked for him in the past, but knew that he’d done a good enough job that the manager might be interested in working with him again. So, it’s not unusual at all that the manager would call the author when he had work to be done.

This leaves the probability that the manager would need to hire someone on the day the author needed to find work. That is difficult to determine without a good understanding of what was going on in the industry at that time. I think we can all agree that it is an interesting coincidence, but not a shocking one.

(Submitted by friend of the blog, Brian Hart)

“Oh, well, this would be one of those circumstances that people unfamiliar with the law of large numbers would call a coincidence.”

Coincidence and The Law of Large Numbers

Season1 | Episode 04 The Luminous Fish Effect | Scene 4 The full context:

Leonard: Okay. I’ll let you get back to fixing your eggs. Sheldon: I’m not just fixing my eggs … (waving spoon) … I’m fixing everyone’s eggs. Leonard: (bowing) And we all thank you. (Sheldon gathers his cooked eggs and sits on the couch. He lays out a journal next to him and takes a photograph of the journal before scribbling a note. He tastes the eggs and pauses a moment in contemplation.) Sheldon: (scribbling a new note) Use … new … eggs. Penny: (knocks on door and looks inside) Hi, hey. I’m running out to the market. Do you guys need anything? Sheldon: Oh, well this would be one of those circumstances that people unfamiliar with the law of large numbers would call a coincidence. Penny: I’m sorry? Sheldon: I need eggs. Four dozen should suffice. Penny: (uncertain) Four dozen?

Quote source: SheldonFAN.com

[EDITOR: I’m a big fan of The Big Bang Theory, and particularly the way in which Dr. Cooper continually fights for accuracy, precision, truth, and knowledge, all while ensuring to alienate everyone around him as much as humanly possible, driving away everyone but his closest of friends; friends who remain by his side through thick and thin, but mostly only because of the strict written agreements binding them to do so. In this sense Dr. Cooper serves as a constant, incessant reminder of how NOT to do my job while making me laugh.]