Perdomo has been almost 100% literally a two-pitch pitcher. Combined, he threw his sinker & cutter (or slider, depending on what system defines the pitch) over 90% of the time. He apparently flirts with a changeup or some form of splitter, but he didn't throw it much last season. As noted in the pitcher matchup graphic in the lead post, he led the NL in GB% last year. So he's doing that part right. FanGraphs had an article last month about two-pitch pitchers with a brief note on Perdomo -- Interestingly, there were three other Pads arms that made this article's list of two-pitch guys. Clayton Richard, Dinelson Lamet, & Jhoulys Chacín (obv. he's moved on). I wonder if there's a larger strategy here, that if they can get even one guy to add an effective third offering, they'll potentially have uncovered their own TOR ace.