  Doping Pr in 123-systems gives rise to some anomalies, such as TC
suppression. Here, we show that a modification of hole localization theory
based on a geometrical modeling by band percolation theory can put forward a
good explanations for TC suppression for whole range of Pr-doping value. In
this model the central effect of hole clustering is introduced. Also we have
provided some experimental evidences which manifest an agreement between
simulation based on hole clustering effect and the experimental data.
