Raymond began his football coaching career in 1951 as an assistant at the University of Maine. He moved to Delaware in 1954 as a backfield coach under David M. Nelson, who had also played at Michigan. Raymond succeeded Nelson as head coach in 1966. He retired after 36 seasons with a 300–119–3 record, three national titles, 14 Lambert Cup trophies, 23 post-season bids and four consecutive victories in the Boardwalk Bowl. After classifications were formed in the early 1970s, Delaware was a Division II program until elevating to Division I-AA in 1981. At the time of his retirement, more than half of Blue Hens' all-time victories in the 110-year-old history of their program had been tallied under Raymond tenure. On March 5, 2002, K. C. Keeler, former Blue Hens linebacker and head football coach at Rowan University, succeeded Raymond at Delaware. Use of "Delaware Wing T" offense A formation similar to the Flexbone, though much older, is known as the "Delaware Wing-T" was created by longtime University of Delaware coach and NCAA Rules Committee chairman David M. Nelson, and perfected by his successor Tubby Raymond. It has become a very popular offense with high schools and small colleges. It was designed at the time to be a mix between the single wing and T-formation. It took the motion and run-strength of the single wing, and the QB-under-center from the T. In this variation, there is only one wing back, with the other back lined up next to the fullback on the opposite side from the wing back. However, the Wing Back may also line up diagonally from the Tight End. He may be used as an extra blocker or a receiver. He may come in motion for running plays.
300th win
Going into the 2001 season, Raymond needed just four wins to reach the 300 mark. At the first game of the season, a banner hung above the stadium listing the numbers 297, 298, 299 and 300. As each win was accomplished, the respective number was crossed off. Raymond's 300th win came during the last home game of the season on November 10 with a 10–6 victory against the Richmond Spiders. As the clock wound down in the game, the crowd began chanting "Tubby, Tubby". Raymond made a short, humble speech and was carried off the field by his team as a construction worker climbed onto a cherry-picker to cross off the final number on the poster. The following is an excerpt from Raymond's speech to Delaware fans after his 300th victory:
"I have to apologize for paraphrasing, but I feel a little bit like Lou Gehrig. I'm the luckiest man on the face of the earth. First, I'd like to thank the Delaware fans who have been here for so many years. I know there are things that happen that you don't like. There are things that happen that I don't like. But the thing that's there all the time is you. You're at every football game. You're excited about being here, and you truly made Delaware football something we can all be proud of. Thank you very much."
Delaware lost its final game of the season on the road against Villanova and, that winter, Raymond announced his retirement, ending his career at an even 300 wins.
Raymond became involved in Delaware politics, and remained active even after retiring to Landenberg, Pennsylvania. Because he was well-known and liked in Delaware, his endorsement was sought out by candidates. Raymond was a staunch conservative; he described himself as "just to the right of Genghis Khan." Despite his conservative views, Raymond long supported Democrat Jack Markell more out of loyalty than because of political views. As a boy, Markell grew up seven houses away from the Raymonds and the two remained friends. When Markell ran for state treasurer, Raymond taped radio ads supporting him. In 2007, Markell named Raymond an honorary co-chair of his 2008 gubernatorial bid. Markell became the 73rd Governor of Delaware in January 2009.
Painting
Raymond was an accomplished painter. While coaching at Delaware, he began a tradition of painting a Blue Hen player each week of the season. Even after retiring from coaching, he continued to paint each senior Blue Hen player.
Family
Harold was married to wife, Diane Raymond. Raymond had three children with his first wife, Sue; David, Chris and Debbie. Harold and Diane had a daughter, Michelle.
Head coaching record
Football
Baseball
Below is a table of Raymond's yearly records as a collegiate head baseball coach.