How NOT to win Rock-paper-scissors every time

FlowingData posted a chart created from info from the World RPS Society entitled How Do I Win Rock, Paper, Scissors every time?, which attempts to improve your RoShamBo* (UK: Scissors, Paper, Stone) technique using psychology.

Maybe their psychology is sound, but unfortunately, their grasp of mathematics ain’t so good.

When you see a two-Rock run, you know your opponents (sic) next move will be Scissors or Paper. People hate being predictable and a firm indication of predictability is to come out with the same throw three times in a row. Counter with Rock.

If you “know your opponents [sic] next move will be Scissors or Paper,” don’t throw Rock. Because then you have a 50% chance of winning, and a 50% chance of losing. No sir! You want to throw Scissors, with a 0% chance of losing and a 50% chance of winning.

I admit, it doesn’t give me much confidence in the rest of the chart.**

Even more interesting to me was the link to the International RoShamBo programming competition that Sean posted in the comments. Fascinating!

(via @bobacks)

* I still can’t read the word RoShamBo without hearing Cartman shout “I’ll kick you squar in the nuts!”

** I’ll leave the analysis of the strange phrase: “a firm indication of predictability is to come out with the same throw three times in a row” to the linguists out there.