This goes back to LL all stars. But the point is the same at any level. Twice my son caught six innings and pitched the seventh when the game went into extra innings. Both times a kid with great control was all over the place. One time he struck out three and walked three. The other time he went high in the count to all three hitters. His legs were tired. When legs get tired pitching mechanics can be altered. Altered mechanics can lead to arm problems. These two games were the only time in his baseball journey he did this. I told the head coach it wasn't happening twice in the same tournament. He did it once each at districts and sections.