whatTwelve rows of staggered pegs, balls raining through, bins filling stroke by stroke like a tally kept in ink. Every peg is one coin flip: left or right, nothing else.

whyThe claim: the bell curve assembles itself out of pure coin flips -- no ball knows about the others, no one aims for the middle, and yet the pile takes the binomial's shape every time. It is measured, not admired: the dashed envelope is the prediction from the pegs' own measured bias, the total-variation distance between pile and prediction shrinks as the balls accumulate, and the pile's spread lands on sqrt(npq). Click a side and every peg leans: the pile follows, skewed exactly as the leaning prediction says it must.

howEach ball's twelve flips come from its own seeded stream, so the pile is reproducible regardless of frame rate. Changing the bias honestly resets the tally. Bins draw as stacked strokes, at most ninety per bin, darkening as they compress; the print carries the stacks, the envelope, and the measured ledger.