In Lotto under the 6/52 · Jan 2010 – Oct 2012 rules — 442 draws, 6 from 1–52 (an earlier era).
43times drawn · chance expected 51 −1.19σ
11draws waiting · a wait this long: 29% for any number
9.8average wait between appearances · chance says 8.7
34longest completed wait · 52% chance of one at least that long
31 is drawn as often as chance explains
Drawn 43 times in 442 draws against 51.0 expected, −1.19σ. Each draw is independent: after 11 draws away it is exactly as likely tonight as a number drawn yesterday.
31
Number 31, draw by draw
Drawn 43 times in 442 draws · average wait 9.8 draws · longest completed wait 34 · waiting 11 draws now
a completed wait — darker is longer the wait still running — a lower bound, not a finished gap
Where it lands in a sorted draw
Sort a draw and 31 has a favourite seat — chance gives a large number the high positions more often. That is the shape of sorting, not of the machine.
It has shared a draw with every one of the other 51 numbers; chance expected about 0.8 still unmet by now. Every pair →
How many people play it
Under the crowd model, 31 is picked about 1.22× as often as an indifferent choice — 15th most popular of 52. That changes nothing about whether it comes up, and everything about how many ways a jackpot on it would be shared.
Nothing here predicts the next draw. A number’s history is a record of a fair machine’s past, and the machine keeps none of it: 31 is drawn with probability 6/52 tonight whatever it did last week.