At the end of last season, Sandy Alderson was asked in two separate interviews to summarize the season. In both, he referenced how the Mets had performed at home. They had just put the finishing touches on a 33-48 home record, the fourth-worst in all of baseball. In fact, the Mets have performed worse at home in each of Alderson's first three seasons. This ineptitude at home is likely what led to the following response from Alderson, when asked in a late season broadcast by Ron Darling if he will address this poor performance at home during the offseason:

"Yes, and this isn't the first year it's happened, it's three years in a row. I think you have to look at everything from the way the team is constructed to the type of player that can play here as opposed to playing elsewhere. I think you have to look at pre-game activity and a variety of things, and we're going to be looking for input from all kinds of sources, including the players themselves. It's something that absolutely has to be corrected. You know, we thought that changing the outfield fence would have a big impact, and it hasn't had as great an impact as we would have hoped."

Alderson then went on to point out that the team had been about .500 since the middle of June and cited the outfield as one of the sources of this adequate performance. In a subsequent interview with Mike Francesa on WFAN, Alderson again pointed to the poor performance at home before pivoting to the fact that they had been about .500 since mid-June. It may seem like Alderson is bewildered about the home performance, but I think it's likely he already knew how, and why, to fix the Mets.

Tony Blengino, the former stats guru of the Seattle Mariners front office who now contributes to Fangraphs, recently wrote about a unique park factor that affects batters in Fenway Park. Specifically, according to his own proprietary data from his time in a front office, the Red Sox have an enormous park factor in regards to fly balls, especially fly balls to left and center fields. This effect is due to the high walls that turn otherwise routine fly outs into doubles. This was interesting and informative, but the shocking part of the article was the table Blengino provided of his fly ball park factors. Ranking eighth on his list, fourth in the National League, was Citi Field.

How could Citi Field, a known pitcher's park, have an above average park factor on fly balls? Blengino's methodology isn't explained beyond saying he compares the expected average and slugging percentage of fly balls, as calculated by angle and speed off the bat, to the actual average and slugging percentage that occurred. He also doesn't specify the time period the data reflects, so we're left to speculate in this respect.

Citi Field is above average when it comes to home runs, but this has only been the case since the fences were moved in after the 2011 season. And this wouldn't explain it all because Citi Field ranked ahead of several parks that are worse for home runs, such as Cincinnati, Toronto, and Philadelphia. It would help to know more about his methodology, but without further clarification there are two possible explanations for ranking highly on this list: a quirky ballpark and/or poor outfield defense.

We can definitely check off poor outfield defense for the Mets. According to Fangraphs, from 2009 through 2012 the Mets ranked 27th in outfield defense, including last in both 2011 and 2012. As for the quirkiness of the ballpark, there isn't any one thing that would lead to an increase in extra base hits. It's easier to hit a home run to left field now that the Party City Deck has replaced the Great Wall of Flushing, and perhaps right center is cavernous. Let's assume the model controls for defense at least somewhat and accept that there is something about Citi Field that leads to an increase in extra base hits on fly balls. If you had this information, what would you do with it?

The first thing you would do is never play Lucas Duda in the outfield ever again. The next thing you might do is to replace him with an above-average defender. You might also consider upgrading the rest of your outfield defense, if possible. It hardly seems like a coincidence that Lucas Duda played his last game in the outfield on June 16th, just three days before the Mets acquired Eric Young. This also coincided with Juan Lagares beginning to take over the everyday job in center field. Is it a coincidence that from mid-June through the end of the season the Mets played .500 baseball? Probably. But from the day Duda played his last inning in left to the day the Mets waved the white flag and traded Byrd, they were two games over .500. Could Alderson have been on to something?

The first thing you would do is never play Lucas Duda in the outfield ever again.

In a post for the Hardball Times, Jeff Zimmerman got his hands on data from Inside Edge, a system that can track fly ball data. The post has lots of interesting data and is well worth a click, but two things jump out. First, an above average number of fly balls were falling in for hits against the Mets. Put another way, the Mets were really bad at recording outs when the other team hit fly balls. Second, the Mets got really good at recording outs on fly balls once Juan Lagares and Eric Young started getting regular playing time, going from well below average in April and May to well above from June through September.

Earlier this offseason, Andrew Koo of Baseball Prospectus put out a fascinating piece of research on the Oakland A's and the new market inefficiency they were exploiting. It turns out that fly ball batters have a lot of advantages over ground ball batters,and the A's have been hoarding them. Oakland led the league in fly ball percentage last year, followed by Boston and Tampa Bay according to Baseball Prospectus, which probably isn't a coincidence. This research alone makes a compelling argument for having fly ball hitters over ground ball hitters. However, if your team has a park effect that favors fly balls, as Blengino's table suggests the Red Sox and, supposedly, Mets do, it would make sense to fill your team with quality defenders in the outfield who also hit lots of fly balls.

This past offseason was Sandy Alderson's first real opportunity to shape the Mets as he saw fit. Unshackled from the Johan Santana and Jason Bay contracts, Alderson had the flexibility and resources to sign big dollar free agents. His first move was a one-year deal for Chris Young, who had been cast aside by the A's. The next deal was the big one, signing Curtis Granderson to a four-year deal. These players share similar traits in that they both play excellent outfield defense and hit a lot of fly-balls. Young hit 49.8 percent of his balls in play in the air last year and 48.2 percent of the time for his career. Granderson hit 43.7 percent in 2013 and has hit 44.2 percent in his career. For reference, the major league average in 2013 was 34.3 percent. If your ballpark had a factor that made fly balls more dangerous, aren't these the kind of players you would want to bring in?

If your ballpark had a factor that made fly balls more dangerous, aren't these the kind of players you would want to bring in?

Some may point to the signing of Bartolo Colon and say that he is a fly ball pitcher and that this inconsistency disproves the theory. Yes, Colon allows an above average number of fly balls, but not by so much that you would shy away from signing a pitcher of his quality. In 2013 he allowed 37.9 percent fly balls versus the league average of 34.3 percent. Regardless, the Mets now have the outfield defense that can support this kind of pitcher. And it's a good thing they do, because their projected rotation isn't exactly stacked with ground ball pitchers, especially if Jenrry Mejia is left out.

It seems Alderson had a specific plan in mind this offseason. He wanted to upgrade the outfield defense and he wanted fly ball hitters. He wanted players with this profile because—through some combination of a quirky park factor and perhaps poor defense—Citi Field is susceptible to balls hit in the air, and he wants to use this factor against opposing teams. If it works, perhaps Alderson will have solved the riddle of Citi Field.