The same target distribution sampled by three chains, each being characterised by a different set  {σ} . The contours map the target distribution, which in turn depends only on the parameters Θ₁ and Θ₂. The starting point in each of the chains is (Θ₁,Θ₂) = (−4.5, −4.5) and all contain 2000 iterations. Both parameters share a common σ-value whose optimal setting is σ = 1. It is important to note that given a sufficiently large number of iterations, all the chains would eventually map out the target distribution, however an optimal choice of the proposal distribution will result in significantly faster convergence.