It was reported that this move was going to happen, but the Washington Nationals officially announced that they called up left-handed pitcher Jackson Kent for his major league debut.This promotion is the exclamation point on the 23-year-old's meteoric rise this season, as he began the year with Double-A Harrisburg before getting moved up to Triple-A Rochester, and now to the big league squad.Going all the way back to the spring, there were some whispers about how much Kent had been impressing this new regime. And he turned that optimism into results, as he dazzled throughout the minor league campaign until the organization felt it was time to give him a shot in The Show.With Kent now officially part of the roster, here are three things fans should know about him.Primarily Uses Three PitchesBlack baseball mitt with a ball inside | USA TODAY Network via Reuters ConnectThe left-hander primarily uses three pitches: a four-seam fastball, slider and changeup. He also has a curveball and a sinker in his arsenal, but so far this season, he has largely used that trio of pitches. He threw his fastball 35.2% of the time with Rochester, while his slider was used 30.1% of the time and his changeup 24.2% of the time.None of them are devastating when it comes to pure stuff. Thomas Nestico of TJStats grades his four-seamer as having a TJStuff+ figure of 98, with his changeup getting a rating of 96 and his slider being his only plus offering at 101.Still, Kent has operated at a high level when it comes to advanced metrics. He has a K rate of 25% with a whiff rate of 32%. He generates chase at a 32.2% clip, and he limits hard contact while inducing tons of ground balls. He combines all of that with a low walk rate, with him handing out free passes only 8.2% of the time. All of those numbers are well above average at the Triple-A level, and that bodes well for him when it comes to translating his success to the majors.Was Dominant at Double-A, Had Some Struggles in Triple-AWhite Washington Nationals hat on top of a black mitt | USA TODAY SportsKent started off the year pitching strong for Double-A Harrisburg despite needing a stint on the seven-day injured list from April 2-12. Across seven total starts, he posted a 2.35 ERA with 38 strikeouts to eight walks over 30 2/3 innings pitched. He had an eye-popping WHIP of 0.88, and he held opponents to a batting average of .176.It became clear that he needed to be challenged further, and the organization wasted little time sending him up to Rochester on May 21. But there, he ran into a bit more trouble. That was to be expected since that was the first time he had pitched against that level of hitter, but he still had a 4.38 ERA across 13 starts. He rung up 67 batters in 63 2/3 innings, and he issued 22 walks. His WHIP was 1.24 with a batting average against of .234. But like mentioned above, his advanced metrics painted a much better picture of what he was doing on the mound.Velocity Is Key to His SuccessWashington Nationals logo | USA TODAY Sports via Reuters ConnectWhat has allowed Kent to flourish this year has been an increase in velocity, as he went from sitting in the low-90 mph range with his fastball to being in the mid-90s at times. However, where he's run into some issues this season has been when he loses that velocity, which is something to keep an eye on during his outings in the majors.The good thing is that Kent doesn't need overpowering velocity to be effective, though. He's been heralded as one of the smartest pitchers in the system, and that should allow him to have success even if he's not blowing pitches by opposing batters. But there is a correlation between his effectiveness and his struggles, and that is directly tied to his velocity, or lack thereof.Still, this is an exciting development for Washington. Kent has the makings of being a regular starting pitcher in their big league rotation for years to come. And if he is able to translate what he's done on the farm into The Show, then that will be a huge boon for this franchise's long-term outlook.Add us as a preferred source on GoogleFollow