Mets fans, rejoice! Or … don’t.

The Mets have surprisingly been one of the more active teams this offseason, picking up Anthony Swarzak, Jay Bruce and now, Adrian Gonzalez. On paper, the Gonzalez signing looks like a reasonable pickup: A-Gon could make for a good bench bat and back up whoever the Mets roll out at first base while playing for the league minimum salary.

Except for one small detail: Gonzalez isn’t backing anyone up. Mike Puma reported Tuesday that Gonzalez appears to be the Mets' pick for starting first baseman in 2018.

Cue the well-deserved “LOLMETS” hashtags on Twitter, because while the Mets have had some awful signings over the years, this one might take the cake.

MORE: Worst. Free agent signings. Ever.

On paper, signing Gonzalez doesn’t seem like such a bad idea. After all, as recently as 2015 he was a well above average first baseman for the Dodgers before they discovered dinger-wunderkind Cody Bellinger. Unfortunately, neither history nor batted ball data are kind to these notions: The Mets might be hoping for far more than they’ll actually get from Gonzalez, even at league minimum.

Off to the butterfly farm with you!

Gonzalez's 2017 season is the biggest argument concerning his future production: he appeared in just 71 games, his season cut short due to back problems. In those 71 games, Gonzalez was an offensive and defensive liability, hitting to the tune of a 69 wRC+ while registering -1.1 fWAR for the season.

Hoping to catch lightning in a bottle has been one of the more popular explanations for the Mets’ signing. The Mets hope that Gonzalez will be able to rebound from his poor 2017 season and regain his stroke. But there are multiple issues with this theory. If someone of, say, Bryce Harper’s age and caliber had a season like Gonzalez’s, then a rebound would be much more likely. But Gonzalez will turn 36 this May, and his best seasons are far behind him.

How likely, then, is it that Gonzalez will bounce back?

To examine the odds of Gonzalez rebounding, I compiled a list of all seasons by position players from 1871 to 2017 that were like Gonzalez’s 2017, in three respects.

Each player was 35 years old or older (Gonzalez was 35 in 2017);

Each player was worth -1.0 fWAR or less in 2017 (Gonzalez was worth -1.1 fWAR) — each of these players had bad seasons for one reason or another, be it injury or bad luck, just like Gonzalez;

Each player recorded at least 250 plate appearances that season (Gonzalez finished 2017 with 252 PA).

I found 85 seasons that were like Gonzalez’s’ 2017 and compiled their fWAR totals for the season immediately following the seasons in question. The final results were less than kind to Gonzalez.

MORE: Which players could bounce back in 2018?

Of the 85 seasons compiled, 34 of them resulted in the player never playing baseball again. Whether out of voluntary retirement or simply teams refusing to give them MLB contracts, 41 percent of these players never took the field for another MLB game. Many players see having a season so terrible at this age as a sign to hang up their cleats.

But what if they hung up their cleats prematurely? Might there still have been a spark left in them? After all, for 47 of these seasons, players were still able to find work the season after.

Shaking the magic-eight-ball of statistics, the answer shows, “outlook not so good." Starting-level production is generally set as 2.0+ fWAR, and only four players hit this threshold after having seasons like Gonzalez’s 2017: Carlton Fisk in 1987, Ray Durham in 2008, Tim Wallach in 1994 and Max Carey in 1927. The group as a whole averaged just 0.1 fWAR in the season following their qualifying seasons.

Twenty-seven of those players were worth less than 0 fWAR. In the majority of these cases, teams would have been better off in terms of production signing a replacement level player and starting them over these players.

History isn't kind to Gonzalez’s hopes of being a productive starter in 2018. But what happened to these players might not be indicative of Gonzalez's situation. Perhaps we would be better off examining Gonzalez not through the eye of history, but rather, his own career.

It doesn’t get much better here either

Adrian Gonzalez was arguably one of the most consistently productive first basemen of the past decade. From 2005 to 2015, Gonzalez ranks fifth in fWAR, seventh in home runs and 10th in wRC+ among first basemen. He’s not quite at the same level as future Hall-of-Famers Albert Pujols, Miguel Cabrera and Joey Votto, but he’s up there with Mark Teixeira, Prince Fielder and Lance Berkman.

Unfortunately, all that consistency has gone down the drain in the past two seasons. 2017 was a far cry from Gonzalez's prime: he posted the worst power figures of his career, saw his walk rates decline considerably and he missed significant time to a back injury that may or may not be chronic.

But the Mets aren’t signing the injured Gonzalez, they’re signing him for what he can do while healthy. Unfortunately, that might not even make it worth the Mets’ trouble.

Let’s (unrealistically) assume for a moment that Adrian Gonzalez is fully recovered from his 2017 back troubles. We can look at Gonzalez’s 2016 season, as the last truly representative sample size of a healthy Gonzalez. Unfortunately, though better than his 2017 season, it’s still not pretty.

On the surface, Gonzalez’s production suffered drastically: his 111 wRC+ was the lowest of his career in a full season by 12 points. For context, the average first baseman in 2017 posted a 118 wRC+, so Gonzalez’s level of production would fall well-below average for his position.

MORE: Ranking the top 101 free agents this year

It’s also concerning that Gonzalez’s strikeouts spiked dramatically: his 18.5-percent figure in 2016 was the highest of his career since 2008 and falls well above his career average. Gonzalez’s contact, especially contact on in-the-zone pitches, dropped off from previous seasons which lead to his poor discipline numbers. That’s not an injury problem, that’s Gonzalez getting older and slower.

In addition, while almost every first baseman is an elevating fly-ball home run hitter, Gonzalez stepped dramatically in the opposite direction in 2016, with only 27.5 percent of his batted ball events registering as fly balls, almost 10 percent below his career average.

Elevating the ball more seems like a simple fix, but fly balls don’t always lead to production unless there’s hard contact behind them. Gonzalez has seen his hard-hit rate decline steadily since 2014 from 38.8 percent to 32.8 percent in 2016. Among first basemen with at least 50 fly balls in 2016, Gonzalez posted the third-lowest average exit velocity on his fly balls. All of these trends continued to some degree in 2017 as well, so it’s not just injury or a fluke.

Gonzalez is too slow to beat out grounders, and he doesn’t make strong enough contact to rack up dingers, even when healthy — it’s simply a factor of age. And the Mets certainly aren’t signing Gonzalez for his defense: Gonzalez has consistently graded out as only an average-to-below-average defender for much of his career, and his defense, like his offense, has declined with age.

Gonzalez doesn’t bring much to the table, except for veteran presence and leadership.

On-the-market alternatives

Given the state of the first-base market, it’s quite the head-scratcher that Adrian Gonzalez appears to not only be on an MLB roster but has a starting lineup slot well before many other free-agent first basemen.

Guys like Mark Reynolds, Logan Morrison, and Adam Lind are younger, healthier, and more likely to outproduce Gonzalez in 2018, but they're still waiting on contracts. A one-year deal for any of those guys would not be terribly expensive, but the Mets could feel more confident moving forward with that position.

STAT TO THE FUTURE: It's time to stop relying on batting average

The Mets already locked up Jay Bruce — who agreed to split time between first base and the outfield if necessary in 2017 — and could have expected to do the same moving forward until Gonzalez was signed. The Mets also have Wilmer Flores, who at the very least is projected by the Steamer projection system to out-hit Gonzalez in 2018 (Steamer projects .336 wOBA for Flores and .328 wOBA for Gonzalez). There’s also the potential for Dominic Smith to be called up and take over the first base job (Smith will reportedly begin the season in Triple-A).

Why would the Mets sign Adrian Gonzalez if it’s extremely unlikely for him to produce? Perhaps the answer lies in public perception.

But hey, it’s the Mets. What else did you expect?