How Will Playing in Boston Impact J.D. Martinez's Fantasy Value?

The months-long free agency dance between the Boston Red Sox and J.D. Martinez is finally over. In a union that nearly the entire baseball world knew to be inevitable, the Sox have signed the slugger their lineup so desperately needed to a five-year, $110 million contract that contains multiple opt-out clauses after the second year of the deal.

For at least the next two seasons, Martinez will help a Boston lineup that finished last in the American League in home runs last season, the first time since 1993 they finished last in the AL in dingers. He moves from one hitter-friendly park (Chase Field) to another (Fenway Park), which means it's more than likely he will remain one of the better fantasy options in baseball this season.

Incredible 2017

Last year was a career season for the 29-year-old, who started the year with the Detroit Tigers and then was traded at midseason to the Arizona Diamondbacks. In 119 games (489 plate appearances) Martinez hit .303/.376/.690 with 45 home runs and 104 RBIs. If you prorate those numbers over 160 games, Martinez was on pace to slug 60 dingers -- 60!

Among players with at least 450 plate appearances, Martinez's .690 slugging percentage was the highest in baseball, a full 59 percentage points higher than the next closest player, Giancarlo Stanton, the guy who hit 59 bombs last season. His weighted runs created (wRC+) of 166 was third (behind Aaron Judge and Mike Trout), and his 45 homers ranked third in all of baseball, as well.

Martinez's season really flipped in Arizona, where he smashed an incredible 29 homers in 62 games -- a pace of one blast every 2.3 games and one every 8.8 plate appearances. Despite Judge and Stanton getting all the love last year, Martinez was the best slugger in baseball in 2017.

Consistency

Martinez isn't a flash in the pan, either.

Since becoming an everyday starter in 2014, he has put up a slash line of .300/.362/.574 with 128 home runs in 520 games. His per-162-game average over the last four years has been 40 dingers, 110 RBIs and 90 runs scored, and even averaging just 130 games a season during that stretch, he's still at 32 homers and 88 RBIs per season since 2014.

Over the last four years, Martinez is tied -- with Bryce Harper -- for fourth among qualified hitters in wRC+ (148). The players ahead of him are Stanton, Joey Votto and Trout.

Reliability Concerns

The reasons Martinez didn't get a seven-year deal worth more than $200 million are his age (this will be his age-30 season) and his inability to consistently stay on the field.

Just once in his career has Martinez been healthy for an entire season, logging 158 games in 2015 for the Tigers. Other than that, Martinez has never appeared in more than 123 games, including last year, when he managed to suit up for just 119 contests.

While he has been incredibly productive when on the field, fantasy owners should be aware that they may have to do without him for a few weeks during the season if the past is any indication.

Moving To Fenway

Fenway Park has always been considered a hitter-friendly park with the inviting Green Monster in left field and the short porch Pesky Pole down the right field line. However, last year, the Sox struggled to hit homers, with Fenway ranking 26th out of 30 teams in home run rate, according to ESPN's Park Factors. Despite that, Fenway was tied for 11th in overall run environment last year, and it was the fourth-best stadium in which to pile up doubles.

In fact, Fenway has not been a great park for home run hitters in recent seasons, based off Park Factor information. In 2016, it ranked 12th in home run environment, was 19th in 2015, 27th in 2014, and 23rd in 2013. Many balls that would have been homers to left and left-center in other parks clang off the Green Monster and turn into doubles.

The good news is Martinez traditionally hits almost as many homers to right field as he does left -- with 62 of his career homers pulled to left, 55 of his bombs hit the opposite way and 35 smashed to center field. He's not a strictly pull hitter, which should help. In his four-homer game against the Los Angeles Dodgers last season, half of his bombs were hit out to right.

Martinez doesn't have many games under his belt at Fenway, just seven total. But in 29 plate appearances, he's hit .444/.483/.519 with 2 doubles. It's not a big sample size, but a hopeful one for sure.

Where To Draft Him

According to FantasyPros average draft position data, Martinez is currently being drafted 26th overall as the 21st position player taken off the board. Martinez's homer production could be dinged a bit moving to Fenway, but he should pile up the base hits and doubles and continue to be one of the best offensive players in the league.

His inability to stay healthy certainly decreases his value a little, but now that he's going to be a full-time designated hitter, injuries should be less problematic. He should also get a ton of RBI opportunities hitting behind Mookie Betts, Eduardo Nunez and Andrew Benintendi in an improved Boston lineup.

While another 45-homer season is probably not in the cards, a 35-homer, 110-RBI season in which his batting average and doubles numbers increase is likely for Martinez. He's worthy of a late-second or early-third-round pick in 12-team fantasy drafts, and with Martinez's presence in the middle of the lineup, Betts, Nunes and Benintendi should all be bumped up a bit, as well.