X different Opening Day Starting First Basemen in X Seasons (since 1914)
Baseball-Reference takes us back until 1914 and while Retrosheet provides starting pitchers in their game logs, it doesn't have that for other positions.
The top streak includes the final nine seasons of the St. Louis Browns and the club's inaugural season in Baltimore in 1954. The Royals gave it a run after Mike Sweeney called it quits, but Eric Hosmer ended the streak.
A new team will crack this list next month. The Pirates have had a six-year streak with a different Opening Day first baseman, and this season Pedro Alvarez will slide over from the hot corner to make it seven. Two others teams have an active streak of four, and with Milwaukee's pickup of Adam Lind, expect the Brewers to extend theirs to five:
Pirates: Adam LaRoche, Jeff Clement, Lyle Overbay, Garrett Jones, Gaby Sanchez, Travis Ishikawa
Brewers: Prince Fielder, Mat Gamel, Alex Gonzalez, Lyle Overbay
Cardinals: Albert Pujols, Lance Berkman, Allen Craig, Matt Adams
Here's the full list of first basemen from the teams shown above. Some interesting names include an out of place Eddie Mathews in his final season as an Astro, Mickey Mantle manning first base in his final season and Jackie Robinson, who integrated the game with his 1947 debut at first base: