One thing that all major discount stores have in common is a big bin filled with cheap, never-appeared-in-the-theater DVDs. If you’ve ever sorted through one, you know it takes a lot of patience and a little luck to snag a gem from the bottom.

Every year, baseball executives engage in a similar exercise, gathering around the winter free-agent discount bin. Many pull out a few back-of-the-rotation starters, or a couple emergency bullpen arms, or a few utility infielders; most of these players will spend an uninterrupted summer in cities like Winston-Salem, Rancho Cucamonga, or Tulsa.

But some GMs use the discount bin to fill major league holes, and it’s these players who can wind up costing or bringing about a postseason berth.

To evaluate those discount signings that paid off the best in 2005, we’ll use a Baseball Prospectus metric called Value Over Replacement Player (VORP), which measures the number of runs a player has produced above what a freely available player (like Bubba Crosby) would produce given the same number of plate appearances. The players listed in the chart below have varying backgrounds: career minor leaguers finally getting a shot, forgotten major leaguers having career years, or retread relievers no one believed in.

Getting something useful out of the clearance bin is equal parts skill and luck, but intelligent front offices know to look there in the first place, rather than simply dialing Tony Womack’s agent.

Perhaps the only man in all of baseball who expected anything from outfielder Emil Brown was Royals’ GM Allard Baird. Brown had been putting up fairly pedestrian numbers in the minors since his last major league stint in 2001. He signed a minor league deal with the Royals for $335,000 in January, and has since become the team’s third-best hitter. Kansas City has been fielding a Sunday lineup every day for most of the season, so perhaps that’s not as impressive as it ordinarily would be.

But with a .283 AVG/.338 OBA/.440 SLG batting line – good for a 21.3 VORP – the Royals have been the beneficiaries of Brown’s best season, and Brown will likely be able to leverage it into at least another year of major league service.

The Cardinals’ John Rodriguez is essentially Brown in 329 fewer plate appearances, as he’s hit an almost identical .284/.338/.440 in his brief time with St. Louis.

Rodriguez is a bit more high-profile, though, since he replaced the injured Larry Walker on a playoff-bound team. He was an organizational soldier in the Yankee organization until signing with the Cardinals last winter.

As a .270/.353/.461 hitter in the minors, Rodriguez routinely demonstrated that he was no worse than guys like Kansas City’s Terrence Long or ex-Oriole and Twin Marty Cordova – marginal players who nonethe less drew big league paychecks while Rodriguez got to know the nightlife of Columbus, Ohio.

Staying with the Cardinals for a moment, infielder Abraham Nunez was inked to a minor league deal in January for $650,000. A career .238/.306/.316 hitter entering the year, he represents what happens when you just plain get lucky.

Though Nunez’s .303/.358/.401 line (VORP of 17.2) is largely batting-average-driven with little power for a corner infielder, he has nevertheless helped to lessen the damage of the Cards playing without a healthy Scott Rolen. Nunez has actually outplayed Rolen this season. Before undergoing his season-ending shoulder surgery, Rolen was hitting like Nunez used to in his days with the Pirates.

A Yankees castoff after 2004, the Diamondbacks signed 33-year-old Tony Clark to a reasonable one-year, $750,000 deal this winter. With a few young corner infield and corner outfield prospects like Carlos Quentin and Conor Jackson almost ready to step into the majors, the Diamondbacks signed an adequate placeholder in Clark. He responded by hitting a tremendous .313/.363/.645, accumulating the best VORP on the team in the process despite getting to the plate just 292 times.

Clark’s 2005 batting average is his best ever, his OBA is his third best, and his SLG is his career-best by 116 points. But here’s where the other end of the bargain bin can hurt you. Instead of recognizing that they lucked into the best 292 plate appearances of Clark’s career, the Diamondbacks overpaid to keep him around.

Now signed to a two-year extension based on recent production he can’t possibly be expected to duplicate, Arizona has ensured that their younger, cheaper players have nowhere to play.

When the Mets signed Ramon Castro to caddy for Mike Piazza, no one expected him to post almost the exact same rate stats as the aging Mets slugger. But Castro, who struggled for years to find a job in the crowded Florida Marlins’ organization, has done just that: He’s hit .255/.327/.447 to Piazza’s .259/.326/.444, and their VORP totals reflect nothing more than the disparity in playing time for the two. Piazza’s VORP of 20.8 is about what Castro would be worth had he been the starting catcher this year. Considering the average NL catcher has hit .252/.315/.389, Castro’s proven to be an excellent bargain.

The Anaheim Angels proved with their championship season of 2002 that a cheap, effective bullpen can be put to exceedingly good use. That year, the Angels staffed a pen behind Troy Percival with inexpensive and effective unknowns like Brendan Donnelly and Scot Shields.

Derrick Turnbow is a retread from the Angels’ organization, and when he was waived in October of 2004, the Brewers snatched him up, attempting to do what the Angels had done so well a few years ago.

Turnbow became the Brewers’ closer, and has been their best reliever by both traditional and advanced metrics. His 1.79 ERA is tops on the team, and with a VORP of 22.2, he’s even more proof that watching the waiver wire for middle relief talent can pay off.

Roberto Hernandez is another player who has made the most of a minor-league contract. Signed by the Mets for $650,000, he’s posted solid rate stats for the season: He has struck out 8.47 batters per nine innings, and has managed a slightly higher-than-average walk rate of 3.51/9.

Hernandez’s VORP of 17.8 is best among Mets relievers – not bad for a minor league contract.

What the above players all have in common is that they’re all contributing on an everyday basis, and none is in danger of losing his job before the season is out.

What’s more, their combined 2005 salaries add up to less than $4 million.

While veteran players like Womack or Mike Stanton may have a storied history and a little bit of name recognition, there are many more players looking for work each winter who can do a much better job for far less money. Smart GMs know where to look.

Mr. Erhardt is a writer for Baseball Prospectus. For more state-of-the-art commentary, visit baseballprospectus.com.