As we roll on into the second full month of baseball season as small sample sizes turn into substantial numbers that we can rely on, new names start to emerge as 2018's breakout stars. Everyone knows about the elite players, such as Bryce Harper, Craig Kimbrel and Mike Trout, but often forgotten are the lesser known players who emerge as difference makers for their teams.
Here, we'll take a look at a player at each position who is in the midst of a surprising season and deserves more recognition for their accomplishments thus far. We'll also look at if the numbers indicate if their early success is sustainable or the player will fade off later into the season. We've highlighted the transformation and true breakout of Pittsburgh Pirates outfielder Corey Dickerson and catcher Francisco Cervelli, now we'll highlight a breakout player at first base.
Brandon Belt, San Francisco Giants
2018 Statistics - .298/.405/.546, .404 wOBA, 162 wRC+, 8 HRs, .248 ISO, 161 OPS+
Depending on what section of Giants fans you talked to, you'd generate one of two impressions. Belt is either a player who always came close to a breakout but whether due to injuries or some bad luck, never reached the potential he was capable of. The other section of fans would tell you about a player who is greatly overrated, a liability at the plate and someone the team should move on from if they wanted to see greater improvements in their run production.
Last season, Belt's numbers represented a mix of both. Across 451 plate appearances, Belt finished with a .241/.355/.469 slash line but still managed to post a 119 wRC+ and a career-best .228 isolated power. Unfortunately, bad fortune found him from both a medical and performance perspective. For much of his career, Belt recorded a .347 BABIP, 25.8 percent line drive rate and a 35.2 percent hard-hit rate during his time in the majors. While the first baseman maintained the line drive rate (23.4 percent) and even improved his hard-contact percentage (38.4) last season, his BABIP cratered to .284.
The bad fortune didn't end there, it carried over to a much more serious note. On Aug. 4, a curveball by Anthony Banda got loose and hit Belt in the head. Freak accidents like this happen and often times, if the player suffers a concussion, they miss a week of action. In Belt's case, that freak moment cost him the remainder of the 2018 season as concussion symptoms lingered for months as highlighted in Andrew Baggarly of The Athletic's in-depth feature on Belt shows.
Fortunately, Belt's issues are now behind him and a healthy offseason allowed him to train and come into camp ready to try and return to the form we saw from him at the plate in 2015 and '16. Perhaps now, with a further push to increase his launch angle and repeating his hard-hit rates from the 2017 season, Belt could finally unlock more of his raw power and turn soft flyouts and lineouts into doubles and home runs.
We've seen exactly that so far from the 30-year-old. Through 168 plate appearances this season, Belt is on pace for 29 home runs and 33 doubles and set career-best marks in RBIs and runs scored. Behind the increase in power and runs produced, Belt's .298/.405/.546 slash line, .248 isolated power and 161 OPS+ would shatter his highest marks from previous seasons. The greatest jumps come in slugging percentage (.06 bump) and ISO (.02 bump). These are the types of numbers those who firmly believed in Belt's power, contact ability and plate discipline could become if he stayed healthy and it all came together.
The question then becomes what caused this surge in production and the answer can be found in small adjustments made by Belt paired with some of his numbers to the norm for his career. His launch angle this season is up and demonstrates a player who has made a significant change since 2015. According to Baseball Savant's StatCast, Belt's launch angle rose from 15.4 degrees in 2015 to 21 degrees in 2016 and '17 and now sits at a career-best 23.5 degrees.
As a result of the change, Belt's fly ball rate is now over 50 percent for the first time in his career with a 3.1 percent bump from last season (46.9 percent) to now (51 percent). The increase in fly ball rate has helped influenced Belt's HR/FB rate of 15.7 percent this season, which surpasses the career-best 14.1 percent HR/FB rate he set last season. The 30-year-old is also hitting the ball harder than before with an average 89.5 mph exit velocity representing more than a mile per hour bump from his mark last season.
Because of the changes made to drive the ball higher, it comes as no surprise to see Belt's numbers backed up in his expected averages. According to StatCast, Belt's expected batting average (.284) and xwOBA (.439) are close to this current numbers this season and his xSLG (.676) is actually higher than Belt's current slugging percentage. Surprisingly, Belt's slugging percentage (.650) and OPS (1.102) are higher at the pitcher-friendly AT&T Park than on the road, where he holds a .469 slugging percentage and .838 OPS.
One of the greatest changes we've seen from Belt this year is his numbers versus fastballs, which he is seeing 2.6 percent more than he did last season. Against 452 fastballs faced, or 62.6 percent of pitches seen, Belt owns a .333 batting average, .605 slugging percentage and .445 wOBA this season compared to a .256 batting average, .507 slugging percentage and .374 wOBA last season, according to StatCast.
Another area to highlight from Belt is his more aggressive nature at the plate this season. In 2016 and '17, Belt swung at the first pitch less than 37 percent of the time, but this year that number is up to a first-pitch swing rate of 40.4 percent. The veteran knows opposing pitchers want to establish their fastball early and he is ready for it with numbers that clearly back up his decision to swing earlier on.
While his first-pitch swing rate and chase percentage (23.2) are up, Belt remains a very disciplined hitter. He is maintaining his walk rate of 14-plus percent for the third season in a row and kept his strikeout rate under 24 percent for the third consecutive season, according to FanGraphs. When you pair all of this with a higher launch angle, the fourth-most barreled balls hit (21) in the majors and his ability to maintain his line drive rates and overall plate discipline, these numbers aren't surprising.
Even if Belt's batting average dips under .290 with a BABIP regression from .362 to around .340-plus, this is a hitter fully capable of a .270-plus batting average, .390-plus OBP and 25-plus home runs with new career marks set to come across the board. As long as he stays healthy, this should continue to be the year many always thought Belt was capable of and now they can sit back and watch as he establishes himself as one of the best first basemen in the majors.
Numbers courtesy of FanGraphs and Statcast.