Aaron Judge Isn't the Only MLB Rookie Mashing the Ball

Los Angeles Dodgers superstar-in-the-making Cody Bellinger is among the first-year players racking up big numbers.

Aaron Judge has the American League Rookie of the Year award locked up. He might also be the league MVP, and has probably been the most valuable position player in baseball.

By now, there aren't many new things to say about him, especially not after John Stolnis covered Judge for us earlier this week. Surely you've heard about his silly exit velocities and the stupidly-long home runs. His 5.5 fWAR mark leads the majors and is the 15th highest mark for a rookie hitter in the past 50 years. His 197 wRC+ is a mark that only Barry Bonds has bested this century (Judge probably will not sustain that -- regression and all -- but that was a wild sentence to type).

And he still has another half season to go.

Judge isn't the only rookie doing great things this year, though. Cody Bellinger is hitting for tremendous power out in Los Angeles, while Ben Gamel has been one of the season’s pleasant surprises for the Mariners. Here are the season's next four most valuable rookie position players, as ranked by fWAR.

Cody Bellinger, OF, Los Angeles Dodgers

fWAR: 2.3

wRC+: 145

Only four players have hit more home runs than the 22-year-old lefty, who has posted a .261/.342/.619 slash line. The 29.1% strikeout rate has been high but it has hardly mattered, given his 11.3% walk rate and .358 ISO, second only to Judge’s .362 for the big league lead.

Bellinger is also second in the majors in power factor (total bases per hit) at 2.4, behind Joey Gallo (2.6) and ahead of Eric Thames (2.3). PF is an even purer measure of raw power than ISO, and is one of the most predictive offensive stats available. It also seems to predict future home run rate and slugging percentage better than past home run rate, slugging percentage and ISO.

As is the case for Judge, he will almost surely regress in the second half. He has only posted a wRC+ of 145 or greater in one of his minor league stops and FanGraphs projects him to run a 112 wRC+ over his next 296 at bats.

Still, Bellinger seems as close to a lock for the National League Rookie of the Year as Judge is for the AL award.

Ben Gamel, OF, Seattle Mariners

fWAR: 1.7

wRC+: 127

Gamel has gone from Yankees organization castoff to valuable big league producer. In 283 plate appearances, the 25-year-old has a .323/.379/..449 line.

Unfortunately, we have to question whether this will continue to be the case. Much of Gamel’s value relates to his ability to hit for average, but he almost certainly will not be able to continue running a .422 BABIP (his Statcast-based xBABIP is .355, according to

His 8.5% walk rate is right around the league average, while his 24.0% strikeout rate and .126 ISO are both subpar. The strikeout rate may improve, given that his swinging strike and contact rates are better than average.

Unless he continues to be a BABIP outlier, however, he's an excellent sell-high candidate for season-long fantasy players.

Still, his value provided to date has made him one of the game’s better stories, and has been a bright spot for the underwhelming Mariners.

Bradley Zimmer, OF, Cleveland Indians

fWAR: 1.6

wRC+: 109

The athletic center fielder mashed in Triple-A this season to the tune of a 147 wRC+, and has continued to provide value with his bat ever since.

The former first-round pick has hit .285 with a .339 OBP and .450 slugging percentage over 165 plate appearances since getting the call to the bigs in May. Like Gamel, Zimmer has been aided by a high BABIP (.365) and also has subpar strikeout and walk rates (26.1% and 7.3%). His .166 ISO is also below average.

Assuming his BABIP falls, he will be a below average hitter and this is what FanGraphs projects. Still, Zimmer should continue to provide value going forward due to his ability to play a premium position well.

Zimmer has been 6.3 runs better than average defensively as measured by UZR and is +5 by DRS. Also, center fielders have a lower offensive bar to climb than most other players, which is why FanGraphs projects Zimmer to be worth 1.0 WAR the rest of the way despite an 89 wRC+.

Manny Pina, C, Milwaukee Brewers

fWAR: 1.5

wRC+: 101

The Brewers backstop edges out Andrew Benintendi by a tenth of a win to nab the final spot here.

Pina (.287/.328/.457) has been an above average hitter, which is all the more valuable coming from a catcher. The 30-year-old has posted a paltry 4.5% walk rate, meaning his ability to get on-base is almost solely tied to maintaining a high BABIP and low strikeout rate.

So far, so good on both fronts, as Pina has a 19.8% strikeout rate and a .336 BABIP. His strikeout rate is supported by better-than-average contact and swinging strike percentages, though a BABIP dip seems inevitable (it is not even supported by his quality of contact numbers, as his xBABIP is just .302).

Pina also has a .170 ISO that is right around the league average, and this is supported by his batted ball authority (his xISO is .181). Then again, his minor league track records suggests this might be a fluke, as prior to posting a .177 ISO in Triple-A last season, his highest ISO in a minor league season was .164 (it was one of four of his campaigns down on the farm with an ISO higher than .150 since his professional debut in 2006).

It may not continue, but Pina has been one of the many reasons the first-place Brewers exceeded expectations in the first half.