The order parameters defined in Eq. (3) and their corresponding Binder cumulants, Eq. (4a). The results were obtained by SSE calculations of L = 16 systems at inverse temperature β=L . From left to right panels, the coupling ratio defined in Eq. (5b) is h = 0, 0.2, 0.4, 0.6. We use the same colors as in Fig. 5 to indicate the different phases. Large fluctuations close to the phase transition at h = 0.6 are due to simulations trapped in meta-stable states, as is typical in simulations of strongly first-order transitions.