A method, apparatus and computer program products are provided for determining an entry finder from a plurality of merge points of a bounding box for an optimal performance of a differential group pattern match routing. One example method includes identifying each merge point candidate of a plurality of merge point candidates, performing a routability determination process, results of the routability determination process comprises a remaining subset of the plurality of merge point candidates, routing each remaining merge point from the remaining subset of the plurality of merge point candidates, calculating a routing cost for each remaining merge point from the remaining subset of the plurality of merge point candidates, and determining a merge point having a lowest calculated routing cost.