As the trade deadline looms with the Mets just two games out of first place, fans are hoping that GM Sandy Alderson has a trick or two up his sleeve to bring a superstar bat to Flushing. With the amount of pitching the Mets have, it is reasonable to believe that an upgraded offense could take the Mets to the playoffs.

However, fans should be careful what they wish for. If the Mets' history at the deadline tells us anything, it is that trades for superstars have been very hit-and-miss. There have been some instances where the Mets have found solid contributors via trade, but others that resulted in giving up star prospects while netting little in exchange.

For most of the first quarter-century of Mets baseball, the Mets were pretty quiet at the deadline. They made several significant mid-June trades such as the acquisitions of Donn Clendenon in 1969 and Keith Hernandez in 1983, who both eventually contributed to championship teams. The atrocious "midnight massacre" deal that sent Tom Seaver to Cincinnati in 1977 also happened in mid-June, as did the Lenny Dykstra and Roger McDowell for Juan Samuel trade. But at the deadline, they were much less active. It is not until the late 1980's that the team began making significant deadline deals.

The first truly big deal the Mets made at the end of July came at the deadline in 1989. On July 31 of that year, the Mets sent pitchers Rick Aguilera, Kevin Tapani, and three other prospects to the Twins for Frank Viola. Viola was the reigning AL Cy Young Award winner, and was acquired as the Mets were seeking their third playoff appearance in four years.

This was ultimately a fruitless endeavor, as the Mets finished six games behind the Cubs for the NL East crown. Although Viola pitched with the Mets until 1991 and won 20 games in 1990, the Mets never made the playoffs during his tenure with the team. Both Aguilera and Tapani became key members of the Twins' 1991 World Series team, and Aguilera became a three-time All-Star with Minnesota.

On the same day the Mets welcomed Viola to Gotham, they also said goodbye to an old friend, as outfielder Mookie Wilson was traded to the Blue Jays for Jeff Musselman. This was just over a month after the team shipped out McDowell and Dykstra, when the team was making an ill-fated effort to rebuild on the fly by trading several key contributors to the 1986 team.

As the dismantling of the 1986 team and a variety of overpaid, unsuccessful free agents made the Mets one of the worst teams of the early and mid 1990s, the team traded Bobby Bonilla to the Orioles for outfield prospect Alex Ochoa and journeyman outfielder Damon Buford.

Although he is commonly looked at as a bust by Mets fans, Bonilla played very well for the team in 1995, batting .325/.385/.599 with 18 home runs and 53 RBI in 80 games at the time of the trade. This play demanded what looked like a solid return, as Ochoa was Baseball America's 35th-best prospect following the 1994 season. However, he never panned out as an everyday outfielder, and was traded to the Twins after the 1997 season. Buford played in just 44 games for the Mets and was traded in the following offseason.

The following year, the Mets were once again far from contention at the deadline. However, that did not stop the team from making a splash that July. On July 29, 1996, the Mets acquired All-Star second baseman Carlos Baerga from the Indians in exchange for second baseman Jeff Kent and shortstop Jose Vizcaino. A three-time All-Star, Baerga became the first second baseman since Rogers Hornsby in 1922 to post consecutive seasons of 200 hits, 20 home runs and 100 RBI when he did so in 1993.

After the trade, he was never the same player. He batted an unimpressive .267/.302/.373 line in two-and-a-half seasons with the Mets from 1996-1998. Meanwhile, Jeff Kent became a five-time All-Star for the Giants, Astros, and Dodgers, and won the 2000 NL MVP with the Giants. He is considered to be one of the best offensive second baseman of all time, and has even gotten Hall of Fame consideration. Vizcaino went on to play another decade for several teams, serving mostly as a utility infielder.

Three years later, the Mets had turned the tides and were once again contenders in 1999. The Mets were very active, as they made three trades that affected them immensely in both the short and long term.

The series of transactions began on July 23 when the Mets acquired outfielder Darryl Hamilton from the Rockies in exchange for outfielder Brian McRae and pitchers Thomas Johnson and Rigo Beltran. Eight days later, they acquired pitcher Kenny Rogers from the A's for pitcher Leo Vazquez and outfielder Terrence Long. Both Hamilton and Rogers helped the Mets immensely down the stretch; Hamilton batted .339/.410/.488 after the trade and Rogers went 4-1 as the Mets reached the playoffs for the first time in 11 years.

Another trade they made with the A's that July, however, would produce much different results. On July 31, the Mets traded Jason Isringhausen along with Greg McMichael for Billy Taylor. While Taylor pitched in just 18 games for the Mets and recorded an 8.10 ERA, Isringhausen went on to record 300 career saves, pitching primarily for the A's and Cardinals.

The Mets again were players at the trade deadline in 2000. Once shortstop Rey Ordonez went down with a broken arm in May, the team was in need of a shortstop. So the Mets agreed to a trade with the Reds that would send Barry Larkin to New York. But then-GM Steve Phillips refused to commit to Larkin beyond the 2000 season, so the Hall-of-Fame shortstop refused to waive his no-trade clause. The Mets settled by acquiring Orioles shortstop Mike Bordick in exchange for Melvin Mora and three minor leaguers.

Bordick, who was hitting .297/.350/.481 with 16 home runs in 100 games before the trade, was disappointing in 56 games with the Mets. He hit just .260/.321/.365 with four home runs while committing seven errors in the field. He left after the season, and Mora became a two-time All-Star with the Orioles.

After 2000, the Mets spent much of the first half of the decade at or near the basement of the NL East. Their poor performance was not limited to the field, as two front office moves in the early 2000s involved future stars. In 2002, the Mets sent minor league outfielder Jason Bay and pitcher Bobby M. Jones (the other Bobby Jones) to the Padres for pitchers Jason Middlebrook and Steve Reed. Neither of these players went on to have long careers for the Mets, but Bay was the NL Rookie of the Year with the Pirates in 2004 and hit over 200 home runs in his big league career. The Mets signed him to a four-year, $66 million dollar contract in 2010, but Bay failed to live up to expectations.

Then, in a failed playoff push in 2004, the Mets shipped off top pitching prospect Scott Kazmir to the Devil Rays in exchange for Victor Zambrano. This trade went about as badly as a trade can go: the Mets missed the playoffs, Zambrano started just 38 games as a Met, and Kazmir went on to become a star pitcher for the next decade. This trade will always be regarded as among the worst in team history. While it has been over a decade since Zambrano last pitched in the Bigs, Kazmir is still a good starting pitcher, and currently leads the AL in ERA.

In 2006, the Mets had the best record in the National League, and looked ready to confidently stand pat at the deadline. That was until shutdown reliever Duaner Sanchez suffered a season-ending shoulder injury in a car accident just hours into July 31. With the team in sudden need of a relief pitcher, GM Omar Minaya pressed the panic button, trading outfielder Xavier Nady to the Pirates for reliever Roberto Hernandez and starting pitcher Oliver Perez. Hernandez pitched reasonably well in 2006: He held a 3.48 ERA with the Mets in the regular season and did not allow a run in three postseason outings.

But Oliver Perez became a perennial headache for Mets management for years to come. After an up-and-down two-plus seasons with the Mets, Perez was signed to a three-year, $36 million dollar contract ahead of the 2009 season. Perez pitched poorly after this contract, going 3-9 with a 6.81 ERA in 31 games in 2009 and 2010. The Mets opted to eat the final year and $12 million of this contract rather than have him suit up with the team in 2011.

Speaking of enigmas and bad contracts, the Mets traded for another one of those in 2007. The Mets acquired Luis Castillo from the Twins at that year's deadline for minor league outfielder Dustin Martin and catcher Drew Butera. Castillo played well in 2007, hitting .296/.371/.372 in 50 games following the trade.

If Castillo's time with the Mets would have started and ended here, it would be considered a successful deal for a rental player: Neither of the players that the Mets traded became everyday major leaguers and Castillo contributed usefully to the team. Only that wasn't it, and the Mets signed him to a four-year, $25 million dollar contract following the 2007 season. He struggled over the next three seasons, and was released with Perez in 2011.

Over the last quarter-century, the Mets have had a lot of hits and misses at the deadline through the years. Mets fans must hope that Juan Uribe, Kelly Johnson, and Tyler Clippard will be comparable to the Frank Violas and Darryl Hamiltons of yesteryear and not like the Carlos Baergas and Victor Zambranos. The Mets have many reasons to be optimistic for the first time in a long time, and any trade made within the next two days could make or break a pennant race.