Flip 10 Coins at Once
One press flips 10 coins and shows the sequence, the tally and the longest streak. An even 5-5 split is the single most likely result, and it still only happens 24.6% of the time.
Flip it
Each flip is an independent 50/50 draw from your browser's random number generator. A run of five or six the same way is normal in 100 flips — that is what surprises people most.
10 flips, 1024 sequences
Every one of the 1024 possible sequences is equally likely. Sorted by the number of heads, the shape looks like this:
| Heads | Chance |
|---|---|
| 5 | 24.61% |
| 4 or 6 | 20.51% each |
| 3 or 7 | 11.72% each |
| 2 or 8 | 4.39% each |
| 1 or 9 | 0.98% each |
| 0 or 10 | 0.098% each |
The favourite still loses
5-5 is the most likely single total and it fails 75.4% of the time. A lopsided 8-2 or worse, in either direction, appears in about 11% of runs, roughly one session in nine. Ten heads in a row is 1 in 1024. None of that is evidence that a coin is weighted; it is what 1024 equally likely sequences look like when you sample one.
Expect a streak
Four or more identical results in a row show up in 46.5% of 10-flip runs, and three or more in 82.6%. A streak is the normal case rather than the exception, and no streak of any length makes the next flip anything other than 50/50.
10 flips is a number from 1 to 1000
Read heads as 1 and tails as 0 and ten flips give you 0 to 1023. Add 1, keep anything up to 1000, and re-flip on the remaining 24 sequences, only 2.3% of the time. That is the manual version of 1 to 1000. Shorter: 5 flips. Longer: 20 flips.