By Paul Casella

While not typically known as bargain shoppers, the Yankees may have landed one of the better bargains of the offseason on Monday when they reportedly reached a four-year, $52 million deal with "second-tier" free agent third baseman Chase Headley.

Along with providing the Yanks with some much-needed roster flexibility by freeing up utility man Martin Prado to play elsewhere, Headley's signing could be considered a bit of a steal in comparison to Pablo Sandoval's deal, struck earlier this season.

Sandoval inked a five-year, $95 million deal with the rival Red Sox -- good for an average annual value of $19 million, compared to Headley's $13 million AAV, and Sandoval's production level compared to that of Headley's does not warrant such a sizeable variation.

Though the 30-year-old Headley is two years older than Sandoval and is unlikely to return to his elite form of 2012 -- when he finished fifth in the NL MVP voting -- the numbers suggest the gap between the duo isn't as big as some might think.

For starters, Headley's .371 on-base percentage after joining the Yankees on July 22 this past season was the fifth best among third basemen during that span. He trailed only Adrian Beltre (.405), Anthony Rendon (.383), Josh Donaldson (.382) and Matt Carpenter (.381).

As for Sandoval, his latest round of postseason heroics this October certainly amped up his market. He now has a career .344/.389/.545 postseason batting line over 39 games, including a staggering .426/.460/.702 line with three home runs over 12 World Series contests. While those numbers are extremely impressive, it's hard to argue that Panda has some sort of special "clutch" gene when you consider he went just 3-for-17 (.176) in a limited role during the 2010 postseason.

When it comes to overall production, let's take a look at how Headley and Sandoval have fared in some key statistical categories over the past three seasons. The following statistics are for the 2012-14 seasons combined.

WAR

Headley: 13.6
Sandoval: 8.2

Though Headley is obviously helped by his MVP-caliber 2012 season, the Yanks third baseman also has a 7.3 WAR over the last two years, including a 3.5 mark this past season. Sandoval, meanwhile, has a 6.1 WAR over the last two years and racked up a 3.3 WAR this past summer. Though the players seem to be trending in opposite directions over the last couple seasons, Headley has held his own in comparison to Sandoval. Obviously, this analysis gives a lot of credence to advanced defensive metrics, and we'll have more on that below.

Batting lines

Headley: .262/.352/.429
Sandoval: .280/.335/.424

While Sandoval's batting average is 18 points higher over the past three seasons, Headley still has the edge in both on-base percentage and slugging percentage. Headley's numbers also took a hit from a disastrous start to the 2014 season in which he racked up an unsightly .226/.296/.350 line before the All-Star break. He bounced back to hit .265/.367/.402 over the season's second half, right on par with Sandoval's .279/.324/.415 season line.

Home runs

Headley: 57
Sandoval: 42

Yes, Headley's 31 homers in 2012 once again helped his case in this category -- but the difference over the two seasons since is minimal. Headley has racked up 26 homers in the past two years (13 in each season), while Sandoval has connected for 30 long balls during that time span. Both players spent the majority of this period playing in non-hitter friendly home ballparks, but that's certainly no longer the case for Headley in New York.

Defensive WAR

Headley: 2.4
Sandoval: -0.1

Sandoval made some strides defensively this past season, putting up a 0.6 defensive WAR on the heels of back-to-back negative defensive WAR seasons. Still, the 0.6 defensive WAR is Sandoval's second-highest in his seven big league seasons, while Headley has topped that mark in three of the past five years, including this past season when he tallied an impressive 1.7 defensive WAR -- fifth-best among all third basemen.

While some might question the veracity -- or at least pinpoint accuracy of advanced defensive metrics -- it's hard to argue he isn't a superior defender to the corpulent Sandoval.

This is by no means an attempt to make a case that Headley was the better option or will be the better player going forward, but simply a comparison between he and Sandoval, as well as the contracts signed by the two players. Sandoval's age is obviously a key factor, as is his postseason prowess, but the rest of the numbers suggest a rather even balance between the two.

As a result, the all-around production and roster flexibility provided by signing Headley -- at almost half the price of Sandoval, no less -- has to be considered a bargain for the Yankees.

***

Paul Casella is a Sports on Earth contributor and a reporter for MLB.com.