Paul Sewald went from signing a minor league deal at veteran league minimum to being one of baseball’s most effective relievers for a team that just narrowly missed out on the playoffs. Sewald made his debut with the Mets at the age of 27 and just 4 short years later, looks to be one of the best late-game pitchers in all of baseball. How did Paul Sewald go from never having an ERA under 4.50 and a 1-14 career record with the Mets to posting a 3.06 ERA and saving more than 5x as many games in 2021 than the rest of his career? Let’s dive into the numbers.
2021 proved to be a revelation for Paul Sewald when he made the move to the Mariners. Among relievers in 2021, Sewald finished 5th in K/9 with 14.47, 5th in K% at 39.4%, 8th in AVG against at .175, and 6th in SIERA at 2.48. So what has changed last year compared to the other seasons? For starters, Sewald ditched all of his other pitches and made himself a 2 pitch pitcher, throwing primarily a fastball and a slider. Sewald comes in at the 10th lowest release height at 4.7 feet from the ground.
Along with this low release height, Sewald has the 5th lowest VAA (or vertical approach angle) of all fastballs from pitchers who have thrown at least 100 pitches according to Alex Chamberlain’s Pitch Leaderboard. Vertical approach angle refers to the angle the ball crosses home plate. The closer a VAA is to 0, the ‘flatter’ the fastball is and the more negative a VAA, the steeper the ball is when it crosses home plate. Normally, pitchers with a higher VAA will have fastballs that play better up in the zone and guys with lower VAA will normally throw sinkers lower in the zone.
As seen above, according to Fangraphs, Sewald was able to throw his fastball up in the zone at a must higher frequency. The combination of throwing the fastball up in the zone at a higher clip, lowering his release over the years has increased his VAA and made his fastball one of the best in baseball for a reliever. It also helps that the Mariners player development staff has a reputation for getting the most out of players. The Mariners found a diamond in the rough with Sewald who looks to lock in the closer role for 2022.