Category Archives: Off-topic


In The Success Equation, Michael J. Mauboussin makes an interesting point about the role of luck in sports. He frames it in a way I hadn’t thought of before. In sports, any win is part skill and part luck. Different sports depend on different ratios of skill to luck.

Any sport that depended entirely on luck would have all teams normally distributed around a .500 winning percentage (for instance, if competitive coin flipping was a sport). If a win were determined entirely by skill, there would be an even distribution across the spectrum of winning percentages–the best player or team would be undefeated, the worst winless, and everyone else distributed throughout based on skill level. Where a sport lies between these two extremes is a measure of how much luck is in play.

Baseball, on this scale, is about one-third luck. Soccer and football are similar, hockey a little more dependent on luck (53%), and basketball far more dependent on skill than luck (12% luck).

The role of luck is dependent in large part on parity. If two players are exactly equal in skill, then by definition luck would determine the outcome. Basketball teams, because they are restricted mostly to very tall people (and the average height has been rising over time), have a much smaller population of potential players, which leads to a higher variance of skill (the larger the pool of potential players, the easier it is to stock teams with players near the upper limit of skill).

Isn’t that interesting?

How can we determine the role of luck in the success of instruction?

Small Buffy Hiatus

I’ve really enjoyed Joss Whedon’s work over the years, especially Firefly and The Avengers, so I’ve found myself recently sucked into Buffy the Vampire Slayer, which I’d never seen and which has interfered with my web journal time.

I just finished the final season. Nice premise for closing the series, but I found the “chosen one” aspect reminiscent of midi-chlorians, with the same problem: why should being a Jedi or a Slayer depend on some preexisting condition that is out of one’s control?

Maybe I’m too influenced by Peak and its critique of humanity’s errant belief that talent trumps deliberate practice.

Fixing a Sticky Key on a Yamaha YDP-113

This is obviously off-topic, but could be helpful for anyone searching on “Yamaha YDP-113 sticky key” in the future (or for me if the keyboard develops another sticky key in the future)–that is, a piano key that reliably goes down, but doesn’t reliably come up again.

Key non-obvious things to know:

  • Having the service manual is handy, but instead of the service manual for the YDP-113, you need the service manual for the CLP-110. As far as I can tell, those two models are functionally identical, but the service manual for the CLP-110 includes step-by-step disassembly instructions. The service manual for the YDP-113 only includes lists of parts. I found the CLP-110 service manual here.
  • The service manual tells you how to take out the entire keyboard assembly. This isn’t really necessary. You need to take off the top board, the keyboard cover including the key cover assembly, and the “angle Z.” You don’t need to pull the entire keyboard assembly out, and thus don’t have to remove the end block assembly. All you have to do to the keyboard assembly is pull out the 11 screws and push the assembly back a quarter of an inch or so.
  • Once you have the keyboard assembly pushed back a bit, here is a helpful video for popping out the keys so you can clean them. He’s got a different model, so the helpful bits don’t start until around 3:15 mark, but the keyboard assembly appears identical so everything after that point is very helpful.

The whole thing only requires a Philips screwdriver and a butter knife, and the only part that requires some experimentation is removal and replacement of the keys. Everything else is very straightforward and spelled out clearly in the service manual.

This Is the Best Day of My Life

This is the best day of my life.

Wedding day? Birth of a child? First kiss? What’s so special about today?

All of those were great days, and nothing particularly memorable happened today. I was deliriously happy on my wedding day, but I hadn’t even met my kids yet, and they taught me through their joy and laughter that I could be even happier.

Nothing unusual happened today. But today I have all my memories inside of me. Every day I get to spend time with family, friends, and colleagues, adding more and more richness to my life, making today the best day of my life. Tomorrow will be even better.

The Dark Side of Design

“Would you like the full coverage or just the basic insurance?”

“Would you like us to fill it up for you when you bring it back? We charge $3.10 a gallon, which is pretty close to gas station rates right now.”

In a way, I’m impressed with these two questions typically asked when you rent a car. Both questions must be significant revenue generators. Unfortunately, both questions generate revenue by hiding key information.

The first question fails to present the possibility that you can decline the insurance entirely, presenting your options instead as a binary choice.

The second fails to mention that the car rental firm is going to charge you for an entire tank, not just for the number of gallons they add to it. If you bring back a car with seven gallons of gas in an 18 gallon tank, you are going to pay for 18 gallons, not 11.

The way they’ve worded the questions is clever…but dishonest, I think, and an abuse of design.

The idea of presenting a binary choice when there are more options is powerful, and one that’s useful with children (do you want to wear the green shirt or the blue one today?) to prevent choice paralysis and minimize fuss. And I imagine there are instructional design and/or change management possibilities in the false binary choice. The risk with adults, though, is that once they realize you are presenting false choices, they’ll distrust everything you ask them.

“Based on a True Story…”

It’s gotten to the point where I more or less can’t watch movies based on true stories. My wife rented The Imitation Game a couple of weeks ago and I spent the entire movie doubting that anything I was seeing actually happened that way, anxious to look up all the ways that the filmmakers decided that history wasn’t interesting enough or was too messy to fit a tidy narrative.

I wish every filmmaker exploring history created a detailed footnote website, like this one. I haven’t seen Free State of Jones yet, but I will.

Did I Beat the Market?

Years ago, some friends and I started an investment club, which were popular at the time and which was a great opportunity to learn about investing at an age when we could make a real difference in saving for college for our kids, retirement, and so on. Eventually the club ran its course, but we had some fun, made some money, and learned a lot.

Once the club dissolved, I used the same analysis techniques we used in the club to pick a small personal portfolio of individual stocks.

Ever since I made those investments, I’ve had a item on my master to-do list to regularly revisit my investment choices to determine whether each choice in the portfolio is still a good investment. But, somehow, I never get around to it, so for the most part the portfolio has sat there riding the various waves of the market.

A great deal has been written in recent years about how individual investors, over the long run, cannot beat the market. I decided to test this theory by measuring the performance of my modest portfolio against the market over the same time period, using this site.

I actually wrote the above before I ran the numbers, expecting that I would be trailing or at best equal to the market. But since I purchased my first individual stock, I’m actually beating the market by about 5%. Yay, me!

But the question is whether that gain is worth the risk and time. It took time to research the stocks–whether or not I consider that time worthwhile depends on what I got out of it. The experience may have been valuable just for the learning. However, to the extent that I’ve failed to be very active in my portfolio management suggests that I don’t value the time compared to other activities.

Risk is probably the bigger factor. I own nine stocks*, and I’ve been able to beat the market in part because none of them have collapsed. I’m one corporate scandal away from decidedly not beating the market. An index fund, on the other hand, would be doing 95% as well, but it would be resistant to one company tanking the portfolio.

*Intel, Dentsply, Teva, Rio Tinto, Corning, Cummins, China Automotive Systems, Tessera, and VSS