Boston Red Sox Smart to Pursue Matt Garza Rather Than Ryan Dempster

There’s been recent talk that the Red Sox are interested in acquiring Ryan Dempster. On the surface, it looks like a great move. Dempster leads the majors with a 1.86 ERA and is part of a team that would be willing to part with him, the Chicago Cubs.

However, there’s a number of problems in chasing Dempster.

He’s currently having his best statistical season in his career. By trading for him now, the Red Sox would be pulling the trigger on the ultimate buy-high transaction. Dempster is due for a regression, and it could happen at any time.

The Cubs starter has a career ERA of 4.30, which over his 15 years in MLB has been a tick below league average, according to his 99 ERA+ calculated by Baseball Reference.

He’s also never pitched in the American League, which is commonly viewed as the stronger of the two. Researchers at Baseball Prospectus determined that, on average, pitchers see an increase of about a .7 ERA when they switch from the NL to the AL.

Dempster’s current league-leading ERA is unsustainable. His career mark is higher than both his FIP and xFIP- metrics that measure solely what the pitcher controls: walks, strikeouts and homeruns. They’re calibrated to an ERA scale, and xFIP standardizes all HR/FB percentages.

Dempster’s xFIP totals from 2008-2011 were 3.69, 3.76, 3.74 and 3.70, respectively, and he had an ERA of 3.81 over that time frame. This year? His xFIP is 3.71. That figure should roughly be what his ERA will end up at, a far cry from his current total.

Two reasons he’s done so well this year are because of a career low .242 BABIP and 6.7 HR/FB%. Although, unless he’s R.A. Dickey and has found success with a new pitch at a later age, a 35-year-old pitcher does not suddenly perform that much better.

To top it off, Dempster’s a free agent after the year. Under baseball’s new collective bargaining agreement, teams that trade for players during a season in which they become a free agent after the fact do not get compensation draft picks. Trading prospects for a player who may not sign with them is a risk the Sox shouldn’t be willing to take.

On the other hand, trading for Matt Garza would be a wise move.

The 28-year-old former Ray is younger, has pitched well in the AL East and will become a free agent only in 2014. If the Sox choose to make an investment in him, they’d be getting a pitcher in the prime of his career for at least a season and a half. Depending on how well Boston does over that timeframe, Garza certainly could find reasons to stay with the Sox.

Even if Dempster can keep up his success this year, the fact that he’s a free agent makes a trade for him unwise—especially considering the Red Sox currently have a solid five man rotation.

If they traded for Garza this year, they could limit Doubront and Cook’s innings in 2012, and trot out a rotation of Beckett, Lester, Buchholz, Garza and Doubront next year.

That’s the kind of deal that fans will support; we’ll see in the coming weeks if the ownership agrees.