To put it simply, Karma-yoga means accepting result completely. Unless we watch the mind and recognise thought patterns, this attitude can not be applied effectively. When we watch the mind we find that many times we blame ourselves and many times we blame others repeatedly. This inner blame game goes on unconsciously in the form of mental chatter even if we know what Karma-yoga attitude is. This happens due to the conditioning of the mind. The mind becomes conditioned to blame and all this happens unconsciously. When we start watching the mind, this inner game of blame is no longer hidden and then if Karma-yoga is applied it becomes highly potent and gives peace of mind. Blame after all means the denial or non-acceptance, whereas Karma-yoga is about acceptance. Blaming goes away when there is acceptance. Try to catch yourself when you blame yourself or when you blame others creating repetitive mental chatter (Madhyama Vaani).