I don’t think the Pittsburgh Pirates have had an adequate, consistent first baseman since I was born in 1998. First base has always been a revolving door for the Pirates, with classic names such as Daryle Ward and Randall Simon taking up that mantle from time to time. The Bucs have traded for experienced first basemen at trade deadlines, like Justin Morneau or Derek Lee, and have even tried using castaway third basemen at first, like Pedro Alvarez.
The 2016 off-season saw the Pirates add John Jaso, a catcher from the Oakland Athletics. The plan was apparently to adapt Jaso into a first basemen to try to slam the revolving door shut and see some consistency at first base.