Coin Flip Fairness

Comments debate the randomness, biases, and probability of coin flips, including streaks, same-side tendencies, and methods for fair outcomes from biased coins, often using coin tosses as analogies for chance events.

📉 Falling 0.3x Science
3,149
Comments
20
Years Active
5
Top Authors
#4010
Topic ID

Activity Over Time

2007
5
2008
15
2009
75
2010
31
2011
91
2012
60
2013
86
2014
192
2015
178
2016
163
2017
287
2018
136
2019
168
2020
201
2021
190
2022
430
2023
298
2024
306
2025
217
2026
20

Keywords

e.g OP IMO HH HT NOT dicesites.com TH XOR wikipedia.org coin heads tails flip 50 probability dice 50 50 flips flipping

Sample Comments

ars Oct 26, 2021 View on HN

That shouldn't change anything: https://en.wikipedia.org/wiki/Fair_coin#Fair_results_from_a_...

wanderingmind Mar 22, 2023 View on HN

As good as flipping a coin /s

rexreed Mar 22, 2023 View on HN

Basically, a coin flip. Sounds like not better than chance.

IG_Semmelweiss Jun 23, 2023 View on HN

Flip a coin enough times, it's bound to be tails

dooglius Dec 1, 2025 View on HN

"fair coin" refers to both the probability of heads and tails being equal (which is still justified) as well as the trials being independent (unlikely with 100/200; more likely the "coin" is some imperfect PRNG in a loop)

supernewton Jan 8, 2024 View on HN

Anecdotally, with practice, some people can flip a coin to a desired outcome like 65% of the time. And .65^20 is only around 1 in 10,000.

lovemenot Mar 23, 2021 View on HN

Since neither heads nor tails bias had been hypothesised, 1/512 rather than 1/1024.

smt88 Oct 19, 2021 View on HN

Any random one, just as it's possible to flip a coin and get heads a few times in a row.

ihattendorf Jun 3, 2022 View on HN

Then it becomes an 80k coin toss experiment :)

anc84 Sep 1, 2015 View on HN

A flipped coin could have gotten that same fraction. ;)