Houdini 2b Pro 6CPU finds the answer to all of the *tactics* problems within 4 seconds except for these two: 1q1r3k/3P1pp1/ppBR1n1p/4Q2P/P4P2/8/5PK1/8 w - - 0 1 bm Rxf6; r3r1k1/pbq1ppbp/1pp2np1/4N3/3P4/2P5/PPB1QPPP/R1B1R1K1 w - - 0 1 bm Nxf7; Hi Aser, the first Pos. is Olafsson-Unzicker, Lugano 197...