Boston Red Sox fans are lusting after a big bat this off-season. The biggest name being bandied about is free agent J.D. Martinez. Damian Dydyn takes a look to see what it could cost the Sox in salary to sign him.
J.D. Martinez is a bad defensive right fielder. Fangraphs has him at 7.7 runs saved in 2015, then -17.2 and -7.7 in the past two years. That works out to a three year total of -17.2 runs, or -5.73 per season. As we’ve written before, UZR should be taken in three-year samples if we are looking for a measure of true talent level, and as he’s about to sign a massive free agent contract, we definitely need to get at his true talent level. He should be moved to LF or, more likely, DH, and it just so happens the Boston Red Sox would be looking to slot him in at the latter, while using him sparingly to spell the former. This has led many a fan and some analysts to posit that Martinez is going to be horribly overpaid for a DH.
On the surface, that makes sense. It feels intuitive. It might even qualify as conventional wisdom. But as is usually the case with conventional wisdom, the truth is a bit more complicated. So we decided to take a shot at pinning down what kind of value J.D. Martinez might be able to offer as a designated hitter. That means we’ll have to answer a few questions. The first of which is…
How much value does Martinez lose moving from right field to DH?
This one is actually easier to answer than you might think. When building a holistic stat like WAR, there is a positional run adjustment made based on the position the individual plays. As a general rule of thumb, ten runs is equal to one win. So when we look at a player like Martinez and consult the chart found at this link, we can see that as a right fielder, he loses 7.5 runs per 162 games played. That means that to be a neutral defender, he would need to be +7.5 runs. He isn’t, however. So his actual defensive value has been significantly hampering his total WAR figures.
What’s important here is the difference between right field and DH, which is 10 runs as designated hitters have a -17.5 run adjustment. Is that difference greater than the amount of runs he would lose by staying in the field? Left and right field have the exact same positional adjustment (-7.5) so moving to left wouldn’t be likely to help him much, even though Fenway has a very small left field. Since his last two seasons have had large negative values and he’s now coming off of a ligament injury in his foot, it’s probably a safe bet that his UZR will not be improving going forward. There’s a pretty good chance he’s worth something between his 2016 figure of -17.2 and his 2017 figure of -7.7, which would mean that it’s possible he could be losing more value in the field than he would by making the switch to DH.
What kind of bat does he really have?
This would seem to be a simple question to answer, but there appears to be some disagreement among fans about just how good a hitter J.D. Martinez actually is. The short answer is that he’s elite. I would argue he’s one of the ten best hitters on the planet right now, and is likely to remain a top 10-15 hitter for the next five or six years. But rather than just assert that he’s one of the best hitters in the league, we’ll dig into why.
There are a lot of ways to gauge who the best hitter is, so we’ll touch on a few of them here. We can look at the most recent season, in which Martinez had the 3rd highest wRC+ in baseball among hitters with 450 PAs or more (166), the 3rd most HR (45), and the highest ISO (.387) besting even Aaron Judge and Giancarlo Stanton. ISO is isolated power (SLG minus BA) and attempts to measure exactly how much power a hitter has year to year. There is an argument to be made that he was the best power hitter in the game in 2017. But how consistent is he?
Martinez had his breakout going into the 2014 season after joining the Detroit Tigers. In that span he has the 6th highest wRC+ (148), the 9th highest ISO (.274), and the 10th most home runs (128). Over the last three seasons he ranks 8th in wRC+ (147), 7th in ISO (.284) and 9th in HR (105). No matter how you slice it, he’s a top-ten bat in the sport.
How do we guess at his total production as a DH?
If we are certain that his bat is for real (and we’re pretty certain it is), then one of the simplest ways to take a guess at what his WAR might look like as a DH is to find a comparable player; someone with a similar bat who has played as a DH in the recent past. Luckily, there is just such a player and he happened to play for the Boston Red Sox recently. David Ortiz’s last four seasons produced wRC+’s of 151, 134, 139, and 164. Compare that to J.D. Martinez’s 154, 136, 141 and 166. Now, the comparison isn’t perfect. Ortiz posted mostly higher ISO’s, had 150 HR over 2442 PAs in that span as compared to 128 over 2143 PAs and Ortiz walked a bit more while striking out a lot less.
But at the end of the day, their overall production was in a similar range and for Ortiz that means WAR totals of 3.3, 2.3, 2.9 and 4.5 in his final four seasons. That averages out to 3.25 per year. As a comparison, Martinez was worth 14.6 WAR over the last 4 seasons, good for 3.65 per year, but part of that value hinges on a good year in the field (2015) where he posted a positive UZR. That value would be lost moving to DH, so reducing that value by a win or two isn’t unfair, which brings his per year number down to around Ortiz’s.
How do we convert this to a dollar figure?
The idea behind WAR is to create one holistic number to capture the total value of the player. It’s not perfect, but it gives us a decent idea, and in the case of a DH where we can remove the less stable components (defense and baserunning) that figure can be taken as fairly accurate. But how much is that worth on the free agent market? First we need to establish how much a win (1 WAR) is worth. There are different figures thrown around but Fangraphs estimates as much as $11.1M this winter.
Looking at the bottom chart at that Fangraphs link, we can see that the estimated value of a win in the next five years will go from $11.1M this winter to $11.7M in 2018, to $12.4M, $13.2M and finally $13.9 in 2022. We can extrapolate that to $14.6M in 2023 which gives us an average of $12.82M per season over that span. We can use that number to determine how much WAR Martinez would need to average per year over a six year contract in order to “earn” his contract.
MLBTraderumors.com is estimating he will sign for six years and $150M. While Scott Boras is asking for 8/200 I think we can all agree that he’s likely to come down from there and 6/150 seems as sensible a guess as any. If that’s where his contract ends up, he’ll need to average 1.95 WAR per year to produce that much value on the field. Even if we lower that dollar per win figure to $8M in 2017 and run the same exercise reducing the year to year increase to 0.5 we’d see an average of $9.75M per win which means he’d need to average 2.56 WAR per season to justify the contract.
In other words, 6/150 appears to be a downright fair offer for a hitter of Martinez’s caliber who happens to bring no defensive value to the table. It’s possible he’ll sign for more than that, of course, but how high would it need to go in order to outstrip that 3.25 WAR per year that Big Papi averaged in his last four seasons (the comparison we made for what Martinez is as a hitter right now)? At 3.25 WAR per season with a win costing $9.75M (our low estimate) Martinez would be worth $31.69M per year. With a six year contract, the dollar value would have to reach $192M to eclipse that figure on a year to year basis.
At $12.82M, that 3.25 WAR becomes $41.67M on the open market across those six years. That’s just over $250M of value over that span. Now, I’m not suggesting that the Red Sox turn around and offer 6/250 as a counter to Boras’s 8/200. I’m simply pointing out that the assumption that a DH can’t be worth 6/150 or even 6/200 isn’t necessarily true. If the team can land him for the former, there’s a pretty good chance that there would be some surplus value on the field. Even at 2.5 WAR per year averaged Martinez could produce anywhere from $146.25M to $192.3M in value.
So once again, 6/150 looks like a good place to draw the line. We should see if that holds up in the next few weeks.
Follow Damian on Twitter.