Tom Seaver To Reds, 1977 Tom Seaver from the Mets to the Reds for four players, June 15, 1977: Seaver was well-established as one of baseball's best pitchers when the Mets unloaded him because he was disgruntled. He went 14-3 in 20 starts after the deal, pitched a no-hitter a year later and remained effective for nearly another decade.

Tom Seaver To Reds, 1977 But the primary reason the trade was lopsided is that none of the four players the Mets acquired became a star: Outfielder Steve Henderson and utility infielder Doug Flynn were average major leaguers, pitcher Pat Zachry was a disappointment and Dan Norman nothing more than a pinch-hitter.

Michael Young To Rangers, 2000 Michael Young from the Blue Jays to the Rangers for Esteban Loaiza, July 19, 2000: At the time the deal looked good for the Blue Jays, who were 1 1/2 games behind the first-place Yankees. Loaiza would shore up the rotation and nobody had heard of Young, a minor league infielder.

Michael Young To Rangers, 2000 But Loaiza was ho-hum in 2000 (the Blue Jays finished third) and worse the next two years. Young became the Rangers' shortstop in 2001 and has been rock-solid for 12 years, batting .302, closing in on 2,000 hits and making seven All-Star teams.

Mark McGwire To Cardinals, 1997 Mark McGwire from Athletics to Cardinals for T.J. Mathews, Eric Ludwick and Blake Stein, July 31, 1997: The A's knew McGwire would become a free agent at the end of the season and got what they could for him. Problem was, none of the pitchers they acquired did much of anything. Mathews was a serviceable middle reliever and the other two were busts.

Mark McGwire To Cardinals, 1997 McGwire hit 220 home runs in 4 1/2 seasons with the Cardinals, including a then-record 70 in 1998. He'd hit 52 homers in 1996 and had 34 in '97 at the time of the trade, so the A's knew full well that the 'roided-up Big Mac was the best slugger in baseball.

Lee, Sizemore To Indians, 2002 Cliff Lee, Grady Sizemore, Brandon Phillips and Lee Stevens went from the Expos to the Indians for Bartolo Colon and Tim Drew, June 27, 2002: This is the first of three deadline deals that included Lee, and it was by far the most lopsided. Lee, Sizemore and Phillips all became exceptional players, although Phillips did not blossom until he was traded to the Reds the first week of the 2007 season for pitcher Jeff Stevens.

Lee, Sizemore To Indians, 2002 (Talk about a one-sided deal: Stevens had a 6.27 ERA in 33 appearances before retiring). Colon was 10-4 the rest of the season for the Expos before leaving as a free agent. Injuries kept Drew, the older brother of J.D. and Stephen, from pitching much after the trade.

Sauer, Baumholtz To Cubs, 1949 Hank Sauer and Frankie Baumholtz from the Reds to the Cubs for Harry "Peanuts" Lowrey and Harry "The Hat" Walker, June 15, 1949: Sauer (pictured) hit 27 home runs after the trade and became known as "The Mayor of Wrigley." He hit 32 homers in 1950 and won the NL MVP award in 1952 by hitting 37 homers and driving in 121 runs. Baumholtz was a solid contributor, hitting .325 in 1952.

Sauer, Baumholtz To Cubs, 1949 The Reds got little more than two of the best nicknames in baseball. Lowrey, who had been an All-Star in 1946, hit only .253 with three home runs in a full season in Cincinnati and Walker was traded to the Cardinals after the season despite hitting .318 with the Reds.

Jay Buhner To Mariners, 1988 Jay Buhner from the Yankees to the Mariners for Ken Phelps, July 21, 1988: It was a deal Yankee fans including Frank Constanza had trouble forgetting. In a "Seinfeld" episode he asked George Steinbrenner, "What the hell did you trade Jay Buhner for? He had 30 home runs and over 100 RBIs last year. He's got a rocket for an arm. You don't know what the hell you’re doing!"

Jay Buhner To Mariners, 1988 Phelps, a left-handed DH, was supposed to deliver a pennant, but batted only .224 and was traded the following year. Buhner played right field with the Mariners for 14 seasons, hitting 307 homers and driving in 951 runs.

Keith Hernandez To Mets, 1983 Keith Hernandez from the Cardinals to the Mets for pitchers Neil Allen and Rick Ownbey, June 15, 1983: The Cardinals had gotten outstanding production from Hernandez for nine seasons, including a World Series title in 1982, but he was about to make big bucks so they shipped him to the Mets.

Keith Hernandez To Mets, 1983 They got nearly nothing in return: Allen, an effective reliever with the Mets, failed as a starter for the Cardinals and was sold to the Yankees at the 1985 trade deadline. Ownbey was 1-6 in 20 appearances with the Cardinals before retiring. With the Mets, Hernandez hit over .300 four times, won five Gold Gloves and led them to the 1986 World Series title.

Fred McGriff To Braves, 1993 Fred McGriff from the Padres to the Braves for Melvin Nieves, Donnie Elliott and Vince Moore, July 18, 1993: Already established as one of the game's most consistent sluggers, McGriff was traded because he was approaching free agency. He became even better with the Braves, accumulating 19 homers and RBIs the rest of the way and batting .435 in the postseason. He signed a long-term deal with the Braves and helped them win their only World Series in 1995.

Fred McGriff To Braves, 1993 None of the players the Padres got in return panned out: Nieves hit .231 as a backup outfielder; in about 450 big league games over seven years. Elliott pitched only 35 major league innings and Moore, a power-hitting prospect coveted by the Padres, never made the majors.

David Cone To Yankees, 1995 David Cone from the Blue Jays to the Yankees for Marty Janzen, Jason Jarvis and Mike Gordon, July 28, 1995: The Blue Jays thought they were dealing a pitcher past his prime for three arms they could build their staff around for years. Instead, Cone went 9-2 after the trade to help the Yankees make the playoffs in '95, pitched a perfect game in 1999 and was 60-26 through 1999, including winning 20 in '98.

David Cone To Yankees, 1995 None of the pitchers the Blue Jays acquired made a splash. Janzen was a hot prospect who had a 6.39 ERA in 27 big league appearances. Jarvis and Gordon never made it beyond Double-A.

Smoltz To Braves, 1987 John Smoltz from the Tigers to the Braves for Doyle Alexander, Aug. 12, 1987: This was a classic case of a deal that appeared lopsided in one team's favor for three months, then became apparent in hindsight that the other team did the fleecing. Alexander was 9-0 with a 1.53 ERA and led the Tigers to the AL East title. Then the bubble burst: He was shelled in the playoffs and went 20-29 the next two years before retiring.

Smoltz To Braves, 1987 Smoltz soon became part of one of the greatest rotations of all-time. He came back from an injury in 2000 to become a dominant closer for three years, then went back to the rotation and pitched until age 42, retiring in 2009 with 213 wins and a .579 winning percentage, 154 saves and more than 3,000 strikeouts.

Jeff Bagwell To Astros, 1990 Jeff Bagwell from the Red Sox to the Astros for Larry Andersen, Aug. 31, 1990: The Red Sox needed pitching and dangled Bagwell, a Double-A third baseman who broke into the big leagues the following year, moved to first base, and became the centerpiece of the Astros' offense for 15 years, hitting 449 home runs and batting .297 with an OPS of .948.

Jeff Bagwell To Astros, 1990 By 1994 he was the NL MVP, and along with Craig Biggio was a franchise favorite and integral member of the "Killer B's." Boston won the AL East with Andersen, but the 37-year-old reliever notched only one save in four tries and signed with the Padres the following offseason.

Lowe, Varitek To Red Sox, 1997 Derek Lowe and Jason Varitek from the Mariners to the Red Sox for Heathcliff Slocumb, July 31, 1997: Slocumb had 10 saves and an 0-4 record in '97 after the deal and the Mariners won the AL West. But he pitched poorly in 1998 and was gone. Lowe, who had a 6.96 ERA halfway through his rookie season before the deal, and Varitek, a minor league catcher, didn't seem like much of a haul.

Lowe, Varitek To Red Sox, 1997 But they became Boston mainstays by '98 and helped the team to its first World Series title in 86 years in 2004. Varitek, the team captain, has played 15 seasons for the Red Sox. Lowe was a 20-game winner one year, led the AL in saves in another, and remains one of baseball's most consistent starters.

Lou Brock To Cardinals, 1964 Lou Brock from the Cubs to the Cardinals for Ernie Broglio, June 15, 1964: The worst midseason deal ever occurred a few hours before the deadline one day before Brock's 25th birthday, and was a textbook case of a team coveting a veteran so much that a future Hall-of-Famer was relinquished. Brock was the better player in the short term as well, helping the Cardinals to the 1964 World Series title over the Yankees by batting .348 after the trade.