In 1999 Rainer Buhmann won the German Youth Chess Championships in age group U18 in Oberhof.
In 2007, Rainer Buhmann took second place behind Arkadij Naiditsch at the German Chess Championship in Bad Königshofen.
With this tournament result, Buhmann fulfilled his third grandmaster norm; the title was awarded to him in June 2007.
[2] Rainer Buhmann played for the German national team when they won the Chess Mitropa Cup in 2003.
For the 2006/07 season he moved to SV 1930 Hockenheim, which he led to promotion to the Oberliga Baden on the top board.