A bad coach will show signs of favoritism. He will put certain players, who are often the most talented, on a pedestal. The coach will generally allow these players to play a significant amount of time while allowing the other players little to no time on the field. Bad coaches will often cause the players who are not one of their favorites to feel inferior with a lack of compliments or increased criticism.
A good coach will offer constructive criticism to players about changes that they need to make in order to improve their performance while also letting them know what they are doing right. A bad coach will yell at players when letting them know what mistakes they have made. In addition to putting players down about what they are doing wrong, a bad coach will generally avoid complimenting players on what they've done well.
All coaches want their team to win. A bad coach might only be concerned with winning, however. A good coach will recognize that other benefits come with being on a sports team such as having fun and building friendships. If the team loses, a good coach will hope that they have better luck next time. A bad coach might appear to be angry and yell at the players after the team has lost a game.
Coaches should be willing to help their players make improvements. This generally occurs when players need instruction on how to improve their athletic ability. A bad coach may not attempt to help their team's players make improvements. In some cases, students might also seek help from their coaches on personal matters, such as problems that they are having at home. Bad coaches will not make themselves available to offer support to their players.