Interesting read
https://newsroom.haas.berkeley.edu/winning-coaches-locker-room-secret/
"In a new paper published in the Journal of Applied Psychology, Berkeley Haas Prof. Emeritus Barry Staw and two colleagues, Katherine DeCelles and Peter de Goey, test that question where it counts: the basketball court. Their analysis of hundreds of half-time speeches and final scores from high school and college games found that coaches do better when they shelve the happy talk and bring down the hammer."