Waiting times & non-transitivity (Riis–Paterson)

Choose three length-3 patterns A, B, C over {H,T}, and give each its own biased coin: pA=P(H on coin A), pB=P(H on coin B), pC=P(H on coin C). In each run we flip the three coins independently until each pattern appears; then we compare who “wins first”. Pairwise wins can form non-transitive cycles: A beats B, B beats C, yet C beats A (with random tie-breaks).

← Research demos

Non-transitive region (3D viewer)

McDonald-shaped region: drag to rotate, scroll to zoom, click to select (pA,pB,pC).

Sampling: ready.

Region definition: 0<pA,pB,pC<1 and G_AB(pA,pB)>0, G_BC(pB,pC)>0, G_CA(pC,pA)>0. (These polynomials correspond to the classic length-3 example A=HHH, B=HTH, C=HHT.)

Controls & simulation

Run N Monte Carlo games at the selected (p,q).

Runtime: ready.

At current (pA,pB,pC)

Means are exact; pairwise win probabilities are simulation estimates.

P(A beats B)
P(B beats C)
P(C beats A)
Non-transitive?
E[τ(A)]
E[τ(B)]
E[τ(C)]
Ordering by mean

Simulation results (N runs)

Counts based on first occurrence times in each run.

Comparison Wins Estimated P
A < B
B < C
C < A
Cycle frequency

Each run flips 3 independent coins (A/B/C) until all three patterns have appeared, then records the three pairwise outcomes (with random tie-breaks).