For the Washington Redskins, the 2005 regular season was an unpredictable series of dizzy highs and swampy valleys as the team went from looking like a playoff shoo-in to an NFL also-ran. With only the thinnest post-season hopes remaining, however, the Skins made Tony Kornheiser look like a genius and rattled off December wins even as critical competitors – the Falcons, the Vikings, the Cowboys – hit the skids. It all culminated in yesterday afternoon’s…