Second base is often a position of flux in MLB, but there seems to be a higher rate of new faces in different places in 2020.
The top five guys—Ozzie Albies, Jose Altuve, Keston Hiura, DJ LeMahieu and Ketel Marte (not necessarily in that order)—didn't go anywhere, but 17 of the 30 teams have a projected starter who played fewer than 500 innings at second base for them in 2019.
Some of them are just a product of positional shuffling. Marte was primarily an outfielder last year, but he should be almost exclusively a second baseman now that the Diamondbacks have the other Marte (Starling) to play center field.