Thank you; and is tic-tac-toe really effectively the same as pick-15 (including winning conditions)? That's cool. (I believe it, but will have to do some work to convince myself of it)
The concepts you mention on that page sound useful for respectful product design and I'll add the book to my reading list.
I'd like to offer some kind of value in return, probably reading material, although not sure what to suggest. I guess you might already be familiar with Edward Tufte's books on visual design?
Yes, Tufte's most popular book, The Display of Quantitative Information, is quite good, though he pushes minimalism far too much. Note that Tufte also makes a lot of assertions without evidence to back it up. His philosophy on design is that designers should think really, really hard and just get the design right, completely discounting the value of user testing.
Even writing things down with paper and pencil, this game is hard. However, Don Norman shows how, if you put the numbers into a Tic Tac Toe grid, the game becomes trivial.
This person has a description of the same game plus the tic tac toe grid: http://www.andreweifler.com/which-game-are-you-playing-pick1...
Like the original article, I mention in my classes Roman numerals vs Arabic numerals as a good example of how notation can influence things.
The whole field of information visualization is also a great example of how to leverage the power of human vision to easily see patterns and understand data, which overlaps a lot with notation.