The moment the Knicks burst into the playoff picture was captured in a single image late Saturday night: Steve Francis, standing atop the scorer’s table in Washington, his arms folded triumphantly. It is hard to imagine a more unlikely symbolic snapshot. But then, the Knicks’ season has been one continuous string of unexpected triumphs and buzzer beaters. This is a team that most predicted would again finish near the bottom of the N.B.A. standings. The roster was largely unchanged since last season’s 23-59 debacle.”