Fig 3. Disagreement between MCC and Kappa for $C_{1,0}^{a,b}$ with a = 1, as function of b ≥ 0.

If b > 1, the negative class is underrepresented and systematically misclassified, and the positive class is also mainly misclassified. (a) A zoom of the detail for b ≤ 2. (b) For b ≤ 30.