We present H2V4Sports, a real-time horizontal-to-vertical video converter specifically designed for sports live broadcasts. With the increasing demand of smartphone users who prefer to watch sports events on their vertical screens anywhere, anytime, our platform provides a seamless viewing experience. We achieve this by fine-tuning and pruning an object detector and tracker, which enables us to provide real-time, accurate key-object tracking results despite the complexity of sports scenes. Additionally, we propose a video virtual director platform that captures the most informative vertical zones from horizontal video live frames using various director logic for a smooth frame-to-frame transition. We have successfully demonstrated our platform in two popular sports: basketball and diving, and the results indicate that our technology delivers high-quality vertical scenes that are beneficial for smartphone users and other vertical scenarios.