One can argue Carson Kelly produced his first breakthrough in 2019 when he hit 18 home runs over 111 contests after being traded from the Cardinals to the Diamondbacks. A rough 2020 depressed his draft stock heading into 2021 but those who remained steadfast in their support of the young catcher continue reaping the rewards. 

With nearly one-fourth of the season completed there's seven qualified hitters with more walks than strikeouts. If Kelly logged enough plate appearances to qualify, he'd be tied for first with Jeff McNeill in walks to strikeouts ratio at 1.5. Among players with at least 100 plate appearances, he's second in walk percentage (19.8 percent) behind Max Muncy

Overall, Kelly's in the midst of a current 21-game on-base streak dating back to April seventh. He's played in 21 games with 21 walks against 14 strikeouts while scoring 16 runs with six home runs, 19 RBI, a .313 average and 1.111 on-base plus slugging. Versus his peers at catcher in this time span, he's tied for first in home runs, first in RBI, second in runs along with on-base plus slugging percentage (OPS) and fourth in isolated power (.313). 

For the season he's slashing a robust .333/.481/.615 through 106 plate appearances a .282 isolated power, .460 weighted on-base average (wOBA) and 1.097 OPS. Kelly sits on the precipice of his power peak turning 27 in July, which coincides with late age power breakouts at the catching position. 

Exploring his batted ball data, improved discipline and determining an overall outlook remain important parts of the process when deciding if it's a hot streak evidenced in his on-base streak or a sustainable breakout. Time to dig in. 

Batted Ball Data

Starting with Statcast, Kelly's produced 65 batted ball events in 2021 with nine barrels (13.8 percent), 25 hard hits (exit velocity of 95 MPH or higher) and a massive leap in sweet spot percentage from 32.3 percent in 2020 to 43.1 percent this season. Since this rates quality of contact, so far he checks all the boxes of sowing the seeds of a breakout. 

Next, his expected statistics which also quantify the quality of contact agree with the results to this point. He owns a .324 expected batting average (xBA), a .640 expected slugging (xSLG) and a .457 expected weighted on-base average (xwOBA). While his xBA and xwOBA hint at minor migration the mean, his xSLG suggests the power remains with a chance of a couple more home runs than normal going forward. 

This thought receives support in four of his six home runs rating as no-doubters (out of any MLB ballpark) and his xHR of seven suggests a bit of bad luck, missing at least one home run over his first 100+ plate appearances. Also encouraging, he's using the whole field rather than trying to produce more power by relying on pulling the ball. In order to punctuate this point, check out his spray chart from 2020 when he pulled the ball 40 percent of his batted ball events: 

In 2021, he's started the season pulling the ball only 30.8 percent of the time using the middle of the field and especially the opposite field (27.7 percent) improving his results and power production:

Now it's time to break down his discipline metrics. 

Plate Discipline 

Beneath his strong expected statistics, Kelly's seeing less pitches in the strike zone but adapting well. He's actually improved his zone contact rate in spite of this while reducing his chase rate, swing percentage (down by 7.6 percent) and whiff percent (down 1.5 percentage points). Racking up outcomes in the red on Statcast proves productive. With this in mind, here's his zone profile so far in 2021: 

Covering all points of the strike zone except down and in makes him a tough out this season. When viewing his metrics on Fangraphs, it should be noted his swinging strike percentage movement back towards his 2019 season to 8.7 percent to this point with better Z-Contact (in the strike zone) percent and cutting his O-Swing percentage by almost six points. 

Noting positive runs in the Statcast swing and take chart, he's tied for fifth in the majors at 16 runs:

Rounding up Kelly's barrel percentage to 14, he's one of nine players with one along with a strikeout percentage less than 25 and a contact rate of 75 percent or better. 

Status

Although he showed promise in 2019, this season rates as the actual breakout. Especially in light of the tremendous gains in discipline without sacrificing power. It may take time for his projections to normalize, and it's unlikely he hits .300 or better over the full season, still: 

A run towards 20 or more home runs this year with an average at .275 or higher makes him a massive bargain in relation to his preseason rankings or draft cost. Pay close attention to his approach the rest of the way making sure he continues using the whole field, but his breakout is upon us and he's actually who fantasy players wanted Will Smith to be. 

Statistical Credits: 

BaseballSavant.com

Fangraphs.com

THE BAT and THE BAT X courtesy of Derek Carty

ZiPS courtesy of Dan Szymborksi

Steamerprojections.co