I can only speak for my past past, but when I was playing I chewed out several teammates for making stupid mistakes. I was team captain and I acted as a coach on the field. It works, but I made sure that I didn't make the same mistakes. When a player knows that he has to answer to his teammates, it keeps him on his toes. If a guy had a problem with me getting on him, the team put him in his place at practice. I don't believe that a pat on the back gets the same results.