Even the best of the best have been dealt at or around the Trade Deadline, which was June 15 from 1923-85 and moved to July 31 in 1986. Players can be traded after the Deadline if they clear waivers, and are eligible for the postseason with their new team if they are acquired by Aug. 31.
Here's a look at the roster of many of the biggest names swapped in the middle of the season:
Randy Johnson was involved in two in-season whoppers, first dealt to the Mariners by the Expos in May 1989 and then dealt away to the Astros at the Deadline in 1998, creating bookends on the summertime pitching acquisition -- first as a rising star who became a sensation, then as an established superstar who helped his new team reach the playoffs.
Johnson later became part of one of the greatest rotation duos when the D-backs acquired Curt Schilling in a trade on July 26, 2000. By the following year, the lefty-righty combo was celebrating a World Series title and sharing the Series Most Valuable Player Award.
Another mound star to make news more than once by being traded in-season was David Cone, dealt by the Mets to the Blue Jays in late August 1992, just in time to be eligible for Toronto's postseason roster and win his first World Series ring. Three years later, he was sent to the Yankees three days before the Deadline, helped New York to its first playoff appearance in 14 years, and went on to win four more championships.
In terms of long-term gain, John Smoltz -- another August acquisition -- delivered far beyond reasonable expectations for the Braves after arriving in 1987 from Detroit for veteran Doyle Alexander, winning a National League Cy Young Award and ultimately becoming the only pitcher in Major League history with 200 wins and 150 saves. Alexander went 9-0 for the Tigers, who won their division.
In terms of instant gratification, few can match Rick Sutcliffe, a June 1984 addition for the Cubs, from Cleveland, who led Chicago into the playoffs with a 16-1 record and won the NL Cy Young Award. Lesser known is that the Cubs also added a Hall of Fame arm in Dennis Eckersley three weeks earlier.
Other Hall of Fame pitchers traded around the Deadline include Tom Seaver, who continued to deliver greatness for the Reds after the Mets traded him as a result of a contract dispute in 1977, Bert Blyleven, traded by the Indians to the Twins in an August 1985 waiver deal, and Don Sutton, dealt by the Astros to the Brewers in August 1982. Another possible Hall of Famer, four-time NL Cy Young Award winner Greg Maddux, was traded to the Dodgers twice around the Deadline late in his career.
Among more recent Cy Young Award winners, Cliff Lee stands out with three summer switches (do we hear four?), while CC Sabathia served the Brewers as a quintessential rental in 2008 and Zack Greinke had a stopover with the Angels last year.
Rick Aguilera was a top closer who went at the Trade Deadline, moving to the Twins in the 1989 Frank Viola deal with the Mets, ultimately registering 254 saves for Minnesota.
The Red Sox found a captain in catcher's gear when they acquired Jason Varitek from the Mariners in a deal that also netted them pitcher Derek Lowe for reliever Heathcliff Slocumb. The July 31, 1997, trade stands as one of the most lopsided in history, both Varitek and Lowe becoming big players in Boston winning the 2004 World Series and Varitek becoming a Red Sox legend.
First basemen have been popular Deadline acquisitions. Keith Hernandez, the National League co-MVP in 1979, went from the Cardinals to the Mets for pitcher Neil Allen at the June 15 Deadline in 1983 and changed the face of the franchise, helping lead it to its 1986 World Series title. Other first basemen traded during Deadline season were Mark McGwire, sent from the A's to the Cardinals on July 31, 1997, Fred McGriff, stellar for the Braves after being acquired from the Padres in July 1993, and Mark Teixeira, traded from the Rangers to the Braves in July 2007 and then flipped by the Braves to the Angels a year later -- only to sign with the Yankees that offseason.
And while it's early to put him in the same category, Chris Davis is making a case to join this group with his monster season coming two summers after being dealt to the Orioles from Texas.
Jeff Bagwell, acquired by the Astros in a waiver deal on Aug. 30, 1990, made a tremendous impact on the Houston franchise. He was dealt by the Red Sox for veteran reliever Larry Andersen, whose stay with Boston lasted 15 regular-season games. Bagwell, who switched from third to first base upon arriving in Houston, stayed there for 15 years, establishing what 59.6 percent of the 2013 electorate considered Hall of Fame credentials.
The rest of the infield hasn't been a huge Deadline focus over the years. Nomar Garciaparra, the iconic Red Sox shortstop, was part of a 2004 Deadline-day blockbuster that sent him to the Cubs in a four-team, eight-player deal. Scott Rolen (Phillies to Cardinals in 2002 and Blue Jays to Reds in 2009) and Aramis Ramirez (Pirates to Cubs in 2003) are notable third basemen to have been traded in July.
Few players have made the type of impact Carlos Beltran did in Houston in 2004 and Manny Ramirez did in Los Angeles -- er, Mannywood -- in 2008. Both spurred their teams into the postseason, Ramirez doing it for two years with the Dodgers. Both had limited stays, Beltran leaving as a free agent after the 2004 season and Ramirez derailing his career with drug suspensions, starting in 2009.
Then again, few have changed a franchise like Lou Brock did when he arrived in St. Louis in June 1964 in a lopsided deal with the Cubs that brought the Cardinals a Hall of Famer who surpassed Ty Cobb for the all-time steals record. Meanwhile, Rickey Henderson, the man who topped Brock in steals as well as Cobb in runs, was involved in his share of Deadline or near-Deadline deals -- three of them in his nine-team career.
Gary Sheffield blossomed into a star after his June 1993 trade from the Padres to the Marlins -- for eventual closing legend Trevor Hoffman.
So many stars, so many deals. Over the years, even the best of the best, some of whom eventually find a place in Cooperstown, have changed places in the summertime.