It's been two years since Stephen Drew had a full, healthy season. And so, it has been a considerable period of time since he's resembled one of the top shortstops in the game. And it's possible that he'll never perform at such a level again.

But what if he does? What if, for $9.5 million, the Sox landed one of the more productive offensive shortstops in the game?

Again, the idea represents a long shot. But really, free agency is almost always an exercise in betting on probabilities and possibilities -- using what a player has been to bet (with little certainty) on what he is likely to be and what he might be.

Consider Adrian Beltre, whose one-year, $9 million deal with the Red Sox in January 2010 probably ranks as the second-best free agent signing by the Red Sox behind only the one-year, $1.25 million deal to which the team signed David Ortiz in January 2003.

Beltre was spectacular in 2010, but it was hard to forecast that based on either what he'd done in the previous five years and, more specifically, the previous one year. In 2009, while impaired by injuries, he played in a career-low 111 games while hitting .265 with a .304 OBP, .379 slugging mark and .683 OPS along with eight homers. That was the last installment of a five-year run in Seattle during which Beltre hit .266/.317/.442/.759.

Overall, because of his tremendous defense at third base, Beltre was still a good player -- according to Fangraphs, he averaged roughly 3.1 wins above replacement per season, peaking with a 4.9 WAR in 2006 -- but when the Sox signed him, he hadn't performed at the level of a superstar in six years, since he hit .334/.388/.629/1.017 with 48 homers as a 25-year-old for the Dodgers.

When the Sox signed Beltre, they had no expectation that he would produce such a season. Team officials, prior to the season, hoped that he might perform at a level not only to give them a solid everyday third baseman -- someone capable of playing excellent defense and hitting for power albeit with a modest average and likely below-average on-base percentage -- while producing enough to earn "Type B" free agent compensation, meaning that (under the old rules of free agent draft pick compensation) he would be, according to a statistical model developed by Elias and used by Major League Baseball to determine compensation for free agents, a second-tier performer as a third baseman between 2009 and 2010, good enough to net the Sox a supplemental first-round pick if he left as a free agent.

Beltre performed so well, however, that he earned Type A classification, meaning that the Sox got two draft picks -- a first-rounder and supplemental first-rounder -- when he left the team in free agency. The Sox made a bet and it paid off in a huge way -- beyond even their own expectations -- for not just the 2010 season, when Beltre was a contender for the American League MVP (albeit in a year when the Sox missed the postseason), but also for the future, given that the Sox netted the draft picks that brought both first-rounder Blake Swihart and center fielder Jackie Bradley Jr.

So what to make of Drew? From 2008-10, he looked like he was on the cusp of becoming one of the top shortstops in the game. He was a solid to above-average defender, posting numbers that made him look like the Incredible Hulk when compared to the typical class of players at the position who seem like they're armed with Wiffle ball bats at the plate.

During those three years, Drew hit .277 with a .335 OBP, .465 slugging mark, .800 OPS and 48 homers while averaging 146 games per season. His OPS during that three-year span ranked third in the majors among big league shortstops with at least 1,000 plate appearances, behind only Hanley Ramirez (.917) and Troy Tulowitzki (.883), and ahead of Jose Reyes (.791) and Derek Jeter (.783). His average WAR during the three-year span was 3.1 -- the same as Beltre's during his five-year run with the Mariners. Drew's peak WAR (a stat that compares Drew's value to others at his position) was 5.1 in 2010, better than anything Beltre had done in Seattle; he's one of just six shortstops to have a WAR of 5.0 or better in any of the last three years.

There's an excellent chance that Drew, who hit .223 with a .309 OBP, .348 slugging mark and .657 OPS in 79 games in 2012, including a line of .250/.326/.382/.707 with the Athletics after an August waiver trade sent him from Arizona to Oakland, will never replicate that 2010 career peak.

But there's at least a chance that he could. At 30, he remains in the middle of what should be his prime years. He's not so far removed from standout production for his position that it's inconceivable that he could repeat it. And if Drew can show a modest uptick in his numbers from 2012, particularly those that he posted with the A's down the stretch, then he'd represent a pretty valuable shortstop, with a couple of implications.

First, he'd give the Sox a good player in 2013, a year in which the Red Sox are hoping that a number of players on their roster (Drew, Shane Victorino, maybe Mike Napoli, Jon Lester, Jacoby Ellsbury, Clay Buchholz, Dustin Pedroia, etc.) can rebound from down years in 2012 to boost the team back into contention.

Secondly, if Drew performs at something approximating his 2008-10 levels offensively, there's a chance that he could net the Sox a draft pick next winter. If he has anything close to an .800 OPS as a shortstop while showing roughly average defensive ability, then he'd be a standout in next year's free agent class in a class of shortstops that is otherwise highlighted by Yunel Escobar (on whom the Rays have a $5 million club option, meaning he won't be a free agent if he's any good in 2013), 36-year-old Rafael Furcal, 40-year-old Derek Jeter, and a defensively limited 32-year-old in Jhonny Peralta who seemingly alternates seasons in the .800 OPS range with years in the .600 range.

In all likelihood, none of the other players whom the Sox have signed this winter have much of a chance of netting the Sox a draft pick. The other players signed by the Sox -- deals for Shane Victorino, Jonny Gomes, David Ross, Ryan Dempster, Koji Uehara and (while still in limbo) Mike Napoli -- all received multi-year deals that will conclude after the players are past their prime years.

Drew represents something else, a player who is still relatively young for a free agent, someone not so far removed from his considerable upside who plays a premium position where there's a talent scarcity. If the stars align just so, then Drew has a chance to be the best signing of the Red Sox winter, someone who delivers standout production relative to his peers at shortstop and who could, in the process, position himself for a big payday and, hence, give the Sox a coveted draft pick. 

And if he's not? If he doesn't bounce back completely from the horrific ankle fracture that wiped out the second half of 2011 and the first half of 2012? Then on a one-year deal, even at the considerable sum of $9.5 million, the Sox can cut bait without batting an eye, comfortable with the notion that even though their bet didn't pay off, it was a gamble worth taking.