"My daughter is a talented softball pitcher but when her performance is inconsistent, the coach yells at her from the sidelines."
Tell your daughter's coach about her ADD. Explain that ADDers have difficulty processing verbal instructions. She's not intentionally ignoring or disobeying him - she just does not always understand when he yells instructions to her on the field. Ask that he draw or gesture while explaining plays, or at least try to make eye contact when telling her what to do.
Remember, the real problem for ADDers isn't paying attention. It's tuning out the world. To avoid becoming distracted on the mound, your daughter should try focusing on a mental image or silently repeating a motivational phrase.