Agents of change: Stars lead to WS titles

As this summer's non-waiver Trade Deadline reminded us, it can take just one player to transform a team from second thought to contender. The same principle applies to the flurry of free-agent signings that now mark every offseason.

It is a ritual now four decades old, as this year marks the 40th anniversary of the landmark decision that ushered in the free-agent era. When pitchers Andy Messersmith and Dave McNally successfully challenged the reserve clause that had long limited player mobility, they paved the way for unprecedented parity, with 22 different franchises hoisting World Series championship banners from 1976-2014.

As the following list of 10 of the most impactful free-agent signings describes, many of those October triumphs were the product of bold and savvy acquisitions.

1. Randy Johnson, Arizona Diamondbacks
When the D-backs signed Johnson to a lucrative multi-year contract in December 1998, they were a 1-year-old expansion team coming off a 97-loss season. Nonetheless, owner Jerry Colangelo believed that free agency offered his club a means to short-circuit the rebuilding process. "The quickest way to compete is to concentrate on pitching so we'd have a chance every night," he said.

History would prove Colangelo right, as "The Big Unit" won four consecutive National League Cy Young Awards during his first four seasons with the D-backs. His three victories in the 2001 Fall Classic carried Arizona to a title in just its fourth season.

2. Reggie Jackson, New York Yankees
The Yankees' acquisition of Jackson in November 1976 was worrisome at first, as the boastful slugger publicly feuded with manager Billy Martin. But the self-proclaimed "straw that stirs the drink" silenced his critics in the postseason. During a decisive Game 6 against the Dodgers in the World Series, Jackson's three-home run onslaught yielded an 8-4 victory and the Yankees' first World Series title since 1962. It was a performance that seemed to shock even Jackson himself. "I'm not sure I hit three home runs," he said. "But the ballplayer in me did."

Video: A look back at the 1977 World Series

3. Kirk Gibson, Los Angeles Dodgers
With Gibson leading the way, the 1988 Dodgers won 21 more games than they had the previous season, and Gibson took home NL Most Valuable Player Award honors with 25 home runs and 106 runs scored. But it was not in the box scores that Gibson's impact could best be measured. It was, rather, in the toughness with which he and his teammates played the game. "A good time to me is winning," the slugger told reporters during Spring Training. That tenacity ultimately proved to be the central ingredient in the Dodgers' stunning upset of the Athletics in the 1988 Fall Classic.

4. Manny Ramirez, Boston Red Sox
Despite Ramirez's eccentric approach, "Manny Being Manny" meant putting up a 1.006 OPS and averaging 36 homers and 114 RBIs per season from 2001-07. During the team's improbable run to the 2004 World Series title, Ramirez blasted a walk-off home run against the Angels to win the AL Division Series, then took home World Series MVP honors. "He had a remarkable run here," then-Boston GM Theo Epstein, who signed the slugger in 2000, later said. "He's one of the best right-handed hitters in history."

5. Greg Maddux, Atlanta Braves
Prior to inking Maddux to a five-year deal in December 1992, the Braves were a perennial contender, but afterwards they became a dynasty. "Retrospectively, the industry probably views it as the greatest free-agent signing yet," John Schuerholz, the Atlanta GM who signed Maddux, later said. "By how he pitched, how he prepared and how he competed, he set the tone."

In 1995, the future Hall of Famer finished the year 19-2 with a 1.63 ERA. His three postseason victories, including a complete-game win in Game 1 of the World Series, helped Atlanta capture its first championship.

6. Paul Molitor, Toronto Blue Jays
For the first 15 years of his career, Molitor had been denied the experience of winning a World Series championship. "I've watched many a celebration over the years," he later said. "It isn't easy to watch other players enjoying it, savoring it, when you feel you could have been there and should have been there."

Video: 1993 WS Gm6: Molitor comes up big with three hits

But after signing with the Blue Jays prior to the 1993 season, the 37-year-old proved to be the key ingredient that propelled the Jays to their second straight World Series title. In Toronto's six-game Fall Classic victory over the Phillies, Molitor batted .500 with two homers, eight RBIs and a Series-record 10 runs scored.

7. Jack Morris, Minnesota Twins
Hoping to prove that he could still summon the skills that had made him the winningest pitcher of the 1980s, Morris signed a one-year deal with the Twins prior to the 1991 season. He quickly helped the Twins complete an improbable worst-to-first turnaround, posting an 18-12 regular-season ledger. In the playoffs, he burnished his legend with the season's final act, a 10-inning, 1-0 victory over Atlanta in Game 7 of the World Series that propelled the Twins to their second World Series title in five years.

8. Darrell Porter, St. Louis Cardinals
Porter had been a four-time All-Star with the Brewers and Royals prior to his signing with the Cardinals in December 1980. And despite his struggles with substance abuse, teammates attested to his courage and tenacity. As George Brett once put it, "Darrell always played like it was the seventh game of the World Series."

Porter was thus ready to answer the call in the 1982 postseason. He won both NLCS and World Series MVP honors with a brilliant offensive performance that included a .556 average in a three-game NLCS sweep of the Braves and timely hits in the Cardinals' seven-game triumph over the Brewers in the World Series.

9. Jermaine Dye, Chicago White Sox
After the Sox lost legendary slugger Frank Thomas to a broken foot in 2005, Dye, signed the year prior, picked up the slack. His 31-homer season helped Chicago capture the AL pennant for the first time in 46 years. In the first inning of the World Series, the slugger got the White Sox rolling with a solo home run off Astros ace Roger Clemens. Four days later, he knocked a Brad Lidge slider back up the middle to plate the lone run in a 1-0 victory that sealed Chicago's first World Series title in 88 years.

10. Edgar Renteria, San Francisco Giants
When the Giants inked the veteran shortstop to a two-year deal prior to the 2009 season, the club never expected him to put up an MVP performance in the 2010 Fall Classic. But Renteria came alive, providing the decisive blow in San Francisco's five-game triumph over the Rangers: a dramatic, two-out, three-run homer off ace Cliff Lee in the seventh inning of the clinching contest. The performance marked a fitting final chapter in a 16-year career highlighted by a .333 average in 16 World Series games.