Sure this is blatant example but it stands out as example of one critical job of the/a coach i.e. 'fixing' parts before it causes failure: - ManU is at the top of the league and consistently garners 3pts from games yet the coach sees what is going wrong and moves to fix same before it puts the TEAM in a funk - defensive woes.
http://www.bbc.co.uk/sport/0/football/20569444
http://www.bbc.co.uk/sport/0/football/20569444