A new, exotic phase of mass-deformed N=1 SU(2) super Yang-Mills on R3×S1 has recently been discovered by Tanizaki et al. (2006.01487). Both CP and centre symmetries are broken, suggesting it is neither the traditional confined nor deconfined phase. We seek to explain this phase by identifying it with ‘partial deconfinement’. Furthermore, we use this work to identify CP symmetry breaking with the deconfinement/partial-deconfinement transition for any N at theta=pi, generalising the Gross-Witten-Wadia (GWW) transition beyond large N.