The Top 3 Breakout MLB Stars This 2021 Season

Things aren’t quite back to normal in the MLB just yet, but we are getting closer to some semblance of sports as we knew them before the coronavirus pandemic ravaged the United States. While it may still not be all that of a typical season, all of the main elements still exist, such as the yearly introduction of new stars as they go through their breakout periods.

It’s been quite an exciting season, despite the alarming rate of no-hitters. We have seen a good few players emerge as players who could greatly influence MLB scores with stellar performances on any given night.

We’ll take a look at three of these players in the list below. While there’s still a lot of time in the season as it pertains to things changing, the players noted below certainly have the looks of performers who could keep things going for as long as their teams are involved.

Vladimir Guerrero Jr.

Blue Jays first baseman Vladimir Guerrero Jr. was considered a player to keep an eye on prior to the start of the season. He’s leading the MLB in swing/take runs at 29, and is considered to be the best hitter in the league at the moment. It was thought that he would do much better if he put some height on the ball and it appears he’s been doing just that, registering a lower ground-ball rate, a higher average launch angle, and a higher sweet spot rate.

Guerrero Jr. has nearly doubled his career-best with a 16.1% barrel rate, but his composure at the plate is what’s really brought the best out of him this season. He has been swinging less, but the swings he takes are more valuable. As previously mentioned, he has 29 swing/take runs - the analytic concept places run values to each pitch and can measure a player’s value in various parts of the strike zone.

The 22-year-old is doing less chasing while making the most of the pitches he's seen. His 21 swing/take runs in the middle of the zone are the most in the MLB this season and, should he keep up that sort of discipline, we anticipate a bright future.

Carson Kelly

The Arizona Diamondbacks catcher has only played 28 games this season, having suffered a broken toe, but he ranks in the top 10 in batting average with .381 for players with at least 100 appearances at the plate. He also ranks in the top 10 for slugging percentage with .613, and OPS at 1.103. Kelly leads the league in on-base percentage with .491, besting Mike Trout.

Kelly’s hitting was not very impressive in his first two seasons with the Diamondbacks, but he has made improvements to his game by chasing less balls out of the strike zone. He’s walked in 20.9% of his plate appearances, a huge improvement on the 4.7% from last year. And, while he still doesn’t hit as aggressively, he’s swinging at his pitch more often, which has caused his barrel rate to go up from 4.3% to 13.4%.

His batted-ball data also backs up his numbers, given he’s swinging at pitches he can barrel up while leading MLB with an .458 on-base average. 

Freddy Peralta

Freddy Peralta is having a great season as he leads the Milwaukee Brewers in strikeouts this season and has the fewest hits per nine innings at 4.3 among qualified pitchers. The 24-year-old wasn’t guaranteed to be a starter until a few days before the start of the season, but the Brewers can hardly regret the decision given his performances. Peralta is missing a whole lot of bats and attracting low-quality contact in the air. Thirty-nine of the 96 batted balls he’s allowed this season have been weakly-hit fly balls, which is one of the league’s highest rates at 40.6%, with opponents batting just 1-39 on such pitches.

Peralta was inclined to throw a curveball for his breaking pitch in the past and, while it was effective, he’s opted to use a slider more often, throwing those 32.7% of the time. He’s still throwing the four-seamer but the slider has allowed him to use his curve a bit less. The change has resulted in him allowing a .140 average with 72 K’s in 157 at-bats that end on a slider or four-seamer. 

As teams adjust to a full-season after a pandemic-shortened 2020, young stars will have a chance to make a few trips around the league, showcasing their talents to a fan base that is hungry to anoint baseball's next superstar.