The Nationals are in the midst of rebuilding their pitching staff. Last season, the team was second to last in the league with a 5.35 ERA, trailing only the Colorado Rockies. There are many steps that the team will need to take to improve their pitching, but one potential fix is diversifying their team's pitching arsenal by throwing more splitters.
A splitter is a type of off-speed pitch where a pitcher will hold the ball with their fingers spread in a V-shape around the horseshoe of the seams. The pitch is slower than a fastball and has late downward movement to induce hitters to chase and swing and miss.
Last season, the Nationals threw very few splitters. Jackson Rutledge and Mitchell Parker were the only two pitchers on the team to throw at least 100 splitters last season. Moreover, for these two pitchers, splitters were a very small part of their arsenals. Parker only threw his splitter 10.6 percent of the time, and Rutledge threw his 9.4 percent of the time. The most effective splitter-thrower for the Nationals last season was Kyle Finnegan. His splitter had a run value of plus three last season, and he threw the pitch 37.1 percent of the time. However, the Nationals traded Finnegan to the Tigers last offseason, and he signed a deal to stay with them this offseason.
Splitters are incredibly effective pitches. One key attribute about them is that they are platoon-neutral. Some pitches, like sliders, are only effective against batters that hit with the same hand that the pitcher throws with since the pitches naturally move away from the batter. These pitches are still effective, but most pitchers will not succeed if their only off-speed offering is only reliable against same-handed batters. Splitters, though, are effective against both right-handed and left-handed batters no matter whether the pitcher is a righty or a lefty. By adopting a splitter, Nationals pitchers will have a weapon that they can use in any situation against any batter.
Splitters are also effective because of their reduced spin rate. Pitchers throw splitters at the same axis as a four-seam fastball, but the grip reduces backspin on the ball. With less backspin, the Magnus effect, or appearance that a fastball is rising, is reduced. Batters think that a splitter is a fastball, but as the ball gets closer to home plate, it dives instead of rising or staying on the plane the batter expects. Part of the reason why the World Series Champion Dodgers were so effective was because they had three elite pitchers who threw this dominant pitch.
All pitchers are different, and it is hard for some players to throw splitters. However, the Nationals should try and emphasize the use of this pitch going into next season.