He starts by taking 20 midrange jump shots from five spots on the court. Most go in without touching the rim. While Graves, Bailey, Barlow, and Reynolds stand under the hoop to rebound, Allen is closer to Thomas, offering instruction. The coach had a lengthy pro career in the NBA and in Europe, and he joined the Celtics’ staff in the summer of 2015. He likes to joke that Thomas did not even speak to him during his first month in Boston. After Thomas met Allen he Googled him, and his credentials checked out. They now have a trust rooted in loyalty and friendly jabs.