The Non-Canon Expert explains the reasons within the Star Wars Legends lore why Darth Vader was so uniquely slow, tentative and defensive in his duel with Obi-Wan Kenobi in A New Hope, a vastly different style than was typically seen by Vader when confronting the Jedi survivors of Order 66.
This is a Legends story for Darth Vader with information found within the great Legends novel «Death Star» by Michael Reaves and Steve Perry. I hope that you enjoy it!