"Tactical brilliance" refers to someone's exceptional ability to think quickly and strategically in order to achieve their goals or overcome obstacles in a specific situation or scenario. Full definition
George Osborne's reputation for tactical brilliance had taken something of a battering and David Cameron was tarnished by association. (politics.co.uk)
There was some speculation that Brown had stepped out of the session (totally unnecessary for a state visit) so Hague would have to go up in David Cameron's place, but most of us refused to give Labour enough credit for such tactical brilliance. (politics.co.uk)
Arsene Wenger often gets criticized for his team selection, but his surprise move of dropping Olivier Giroud from the Arsenal starting XI last night seems to have been a stroke of tactical brilliance. (justarsenal.com)