The Seattle Mariners are a Major League Baseball (MLB) franchise based in Seattle, Washington. They play in the American League West division. The first game of the new baseball season for a team is played on Opening Day, and being named the Opening Day starter is an honor, which is often given to the player who is expected to lead the pitching staff that season, though there are various strategic reasons why a team's best pitcher might not start on Opening Day. The Mariners have used 15 different Opening Daystarting pitchers in their 34 seasons. The 15 starters have a combined Opening Day record of 11 wins, 11 losses (11–11) and 12 no decisions. No decisions are only awarded to the starting pitcher if the game is won or lost after the starting pitcher has left the game.
Randy Johnson holds the Mariners' record for most Opening Day starts with six, and has an Opening Day record of 2–0. All of Johnson's starts were in the former home ballpark of the Mariners, the Kingdome. Jamie Moyer has the most starts in Safeco Field, the Mariners' current home ballpark, and has an Opening Day record of 1–2. Mark Langston has the worst winning percentage as the Opening Day starting pitcher with a record of 0–3, all of which were pitched on the road.
Overall, the Mariners have a record of 6–4 at the Kingdome on Opening Day, compared to a 2–3 record at Safeco Field, making their combined home record 8–7, and their away record 3–4. The Mariners went on to play in the American League Division Series (ALDS) playoff games in 1995, 1997 and 2001. Randy Johnson, Jeff Fassero and Freddy García were the Opening Day starting pitchers those years, and had a combined Opening Day record of 2–0.