Shift to run prevention makes sense

The Tampa Bay Rays went from 66-96 in 2007 to 97-65 in 2008. The Seattle Mariners went from 61-101 in 2008 to 85-77 in 2009. Those teams shared a focus on defense and run prevention. And although the Boston Red Sox might not have that sort of hole out of which to climb heading into 2010, it seems clear the team has transitioned from the on-base percentage and power-heavy lineups of its recent title years to a roster focused on run prevention and defense.

During the past decade, teams apparently have acquired a newfound appreciation for defense. Defense, more so than offense, always has been difficult to quantify. However, as teams get a better handle on measuring defense, some are using that facet of the game to improve radically. Following in the footsteps of the Rays and Mariners, the Red Sox appear to have decided that the most efficient and effective way to construct a club at this juncture is to emphasize defense. Manny Ramirez and David Ortiz no longer make up the feared heart of the order that existed on the 2004 and 2007 World Series teams. Instead, teams will learn to fear the Red Sox's defense.

Rather than pay Jason Bay the $60 million or $70 million he reportedly is seeking, the Red Sox decided that paying Mike Cameron less than $20 million was a better investment.

Although a casual observer might look at Cameron's 2009 line of .250/.342/.452 (batting average/on-base percentage/slugging percentage) with 24 homers and wonder how in the world that compares to Bay's line of .267/.384/.537 with 36 homers, there's far more to the story. Bay is an offensive force, but he is a defensive liability.

One way to measure that is with FanGraphs' ultimate zone rating, which converts a player's defensive contributions into runs saved (a positive number) or lost (a negative number) versus the average player while taking into account range, arm, double plays and errors.

By that measure, Jason Bay was at minus-11.5 runs overall in 2007, minus-18.4 in 2008 and minus-13.0 in 2009, all marks that approached the worst in baseball.

Cameron, on the other hand, combines solid-but-unspectacular offense with very good defense. Cameron has a plus-6 UZR per 150 games for the past eight years, while Bay has a minus-8 UZR/150.

That stat compares Bay with the baseline for left fielders while comparing Cameron with center fielders. Thus, in actuality, the gap between their defense is even greater. Consequently, although Bay might be a superior offensive player, the two are very comparable when one looks at the entire picture. Then consider that Cameron was acquired for something approaching $50 million less than what Bay is expected to receive this offseason.

Marco Scutaro's career batting average of .265 and OPS of .721 might look unspectacular at first glance. However, the same line of thinking that brought the Red Sox to Cameron led them to the former Blue Jays infielder. Scutaro, signed for a very affordable $5 million per year for just two seasons, has showed he can be an above-average defensive shortstop. Combine that with being a league-average bat at the position, and that represents a genuine upgrade for the Sox at a position that has been a revolving door throughout the years. Scutaro has gone from 0.3 runs below average in 2006 to 0.6 above average in 2007, 1.9 above in 2008 and finally 4.6 above in 2009. With limited options available, the Sox signed a shortstop with a solid combination of offense and defense to a short-term, low-money deal. That, in turn, figures to have a positive effect on everyone in their rotation.

Based on past performance, with Cameron in left field, more fly balls will turn into outs and fewer line drives will reach the wall. With Scutaro at shortstop, a greater percentage of balls in play will be converted into outs. A run saved on defense is as valuable as a run created on offense.

Finally, we come to John Lackey. His defense at pitcher is of little consequence, but what is important is that he represents another move toward run prevention. The Sox, feeling lukewarm about the offensive options available, decided to pursue another starter. Lackey represents a significant upgrade on a guy like Tim Wakefield. With Lackey in the fold, the Red Sox will improve their run prevention.

Not to be forgotten, Lackey's ability to prevent runs will be aided by Boston's other two additions -- Cameron and Scutaro. Clearly, the three primary moves made by the Red Sox this offseason tie together. The team's actions show it is looking to cut down the number of runs allowed rather than actively looking to increase the number of runs the offense generates.

But wait ... what exactly did the Red Sox's defense look like last season? The fact is, the Red Sox were a poor defensive team in 2009. The team as a whole produced minus-16.3 according to UZR, which ranked 16th in baseball. Some of the teams that saw the largest turnaround in record from 2008 to 2009 include the Mariners (first, plus-85.5), Giants (fourth, plus-51.2) and Rangers (sixth, plus-32.5).

Without a Mark Teixeira-type bat available this offseason, the Red Sox appear to have determined that their best course of action was to improve on defense, an area that left a great deal to be desired in 2009. Although the general reaction to the signings might focus on Cameron's strikeouts or comparatively unimpressive batting line, remember that such a take is missing an entire side of the coin. Swerving a bit from their recent history, the Sox are eschewing the big boppers in favor of slick fielding, less expensive options who will help them prevent runs and allow them to become more well-rounded.

Justin Havens is a researcher for ESPN Stats & Information.