**R – Decision Science News**, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here)

Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.

STREAK RESULTS FOR LIKELY (>50%) and HIGHLY LIKELY (>99%)

From research on the hot hand to the observation that people don’t create enough streaks when instructed to create pseudo random data, the decision science community is pretty interested in the perception of streaks.

One day we got to wonder, how long would you have to flip a coin for it to be more likely than not you would see a streak of length 10? And in this thought experiment, we mean a fair coin and that the streak could be one of heads or one of tails, and finally that more likely than not means greater than 50% likely.

We found a nice Markov chain solution to the problem and figured out the answer for streaks from length 2 to 16. The above graph has the first 10. The answer is that you need to flip 712 times to exceed a 50% chance of observing a streak of length 10.

Next we wanted to see how the number of flips would grow if we wanted to be highly likely of seeing a streak, where highly likely means greater than 99%.

Lastly, we took the results out to 16 flips and plotted the result on a log axis.

Here’s R code to mess around with. The Markov chain but could be sped up a lot by starting the search closer to the likely crossover point.

The post How long do you need to flip a coin to see a streak? appeared first on Decision Science News.

**leave a comment**for the author, please follow the link and comment on their blog:

**R – Decision Science News**.

R-bloggers.com offers

**daily e-mail updates**about R news and tutorials about learning R and many other topics. Click here if you're looking to post or find an R/data-science job.

Want to share your content on R-bloggers? click here if you have a blog, or here if you don't.