Can You Find The Fish In State Names?

The recent Riddler classic offered this intriguing challenge: Ohio is the only state whose name doesnt share any letters with the word “mackerel.” Its strange, but its true. But that isnt the only pairing of a state and a word you can say that about — its not even the only fish! Kentucky has “goldfish” to itself, Montana has “jellyfish” and Delaware has “monkfish,” just to name a few.

By Benjamin Soltoff in r

May 22, 2020

Can You Find The Best Dungeons & Dragons Strategy?

I enjoyed the recent Riddler challenger from May 15th: The fifth edition of Dungeons & Dragons introduced a system of “advantage and disadvantage.” When you roll a die “with advantage,” you roll the die twice and keep the higher result. Rolling “with disadvantage” is similar, except you keep the lower result instead. The rules further specify that when a player rolls with both advantage and disadvantage, they cancel out, and the player rolls a single die.

By Benjamin Soltoff in r

May 15, 2020

How Good Are You At Guess Who?

The most recent Riddler Express gave me an opportunity to refresh some base R notation, as well as combine it with a technique I learned while reading Hadley Wickham’s Advanced R. The challenge is: A local cafe has board games on a shelf, designed to keep kids (and some adults) entertained while they wait on their food. One of the games is a tic-tac-toe board, which comes with nine pieces that you and your opponent can place: five Xs and four Os.

in r

March 8, 2020

How Many More Palindrome Dates Will You See?

I’m currently on paternity leave and in search of quick but interesting programming challenges to stay fresh. The latest Riddler Express provided a quick refresher on string manipulation. If we write out dates in the American format of MM/DD/YYYY (i.e., the two digits of the month, followed by the two digits of the day, followed by the four digits of the year), how many more palindromic dates will there be this century?

in r

February 8, 2020

Winning the World Chess Championship

This week’s Riddler Express from FiveThirtyEight: The World Chess Championship is underway. It is a 12-game match between the world’s top two grandmasters. Many chess fans feel that 12 games is far too short for a biennial world championship match, allowing too much variance. Say one of the players is better than his opponent to the degree that he wins 20 percent of all games, loses 15 percent of games and that 65 percent of games are drawn.

in r

November 16, 2018