Can give you some good info on him.
McKeen's 2022 NHL Draft Guide - It is not that often you see a high-level player spend four years in the USHL. A big and skilled forward, and a former highly touted prospect, Halliday has improved every year in the league, culminating with a dominating breakout performance this season. The Ohio State commit was the USHL’s scoring leader thanks to improvements made to his explosiveness and conditioning. Halliday is also now the USHL’s all-time leading scorer (passing Sean Farrell). In his final year of eligibility, it seems likely that Halliday will finally hear his name called at the draft. He has certainly earned it. You really have to commend Halliday for putting in the work to improve his skating. The improvements made to his first step quickness and his overall agility are extremely noticeable and really helped him to dominate shifts on the regular. Halliday was just an absolute beast at the USHL level this year. His combination of power and skill at the center position is not common on draft day. Ohio State is a really good spot for him too, as he’ll be able to go in there and be an immediate top six forward for them on a quality up and coming team. This is another strong re-entry candidate for this season. - BO
Basically, he really dedicated himself to improving his conditioning (spoke to a few folks about that) and it made a huge difference in his game this year.