MLB trade deadline: 5 deals that led to World Series titles

Is Sonny Gray that guy? Or is it J.D. Martinez? Perhaps Yu Darvish?

There's always at least one major leaguer changing teams at the trade deadline that ultimately contributes and pays off  -- with a World Series championship. 

Teams have less than a week to decide if they want to make a deal -- whether it's for a rental player aimed at helping a team contend in October or for a prospect to help rebuild a franchise.

The flurry of deals between now and Monday's 4 ET non-waivers deadline will provide plenty of noise. But only the World Series will let us know which chip was most valuable.

A look at the last five World Series champions - and the crucial ingredient they added at the deadline:  

2016 – Chicago Cubs acquire closer Aroldis Chapman

• The Deal: Traded by the New York Yankees for minor leaguers Rashad Crawford, Billy McKinney, Gleyber Torres and Adam Warren.
• Deadline impact: Chapman saved 16 games for the Cubs and led the NL with a 15.5 strikeouts per nine ratio (minimum of 25 innings). 
• Postseason moment: Teary-eyed in the dugout after blowing the save in the eighth inning of Game 7 of the World Series against the Cleveland Indians, Chapman recovered to pitch a perfect ninth and becomes the winning pitcher when the Cubs scored in the top of the 10th and held on for an 8-7 clinching victory.

2015 – Kansas City Royals acquire RHP Johnny Cueto and INF/OF Ben Zobrist

• The Deal: Cueto was traded by the Cincinnati Reds for Brandon Finnegan, John Lamb and Cody Reed. Zobrist was traded by the Oakland Athletics for Aaron Brooks and Sean Manaea. 
• Deadline impact: The Royals were cruising, so they could shrug off Cueto's 4-7 record and 4.76 ERA in 13 starts.  Zobrist became a super utility specialist, splitting his time between second base and the outfield 
• Postseason moment: Rebounding from an early exit (8 ER in 2 IP) in Game 3 of the ALCS, Cueto made history by pitching a complete game in Game 2 -- the first by an AL pitcher since Jack Morris tossed a 10-inning masterpiece in Game 7 of the 1991 Fall Classic. Slotted in the No. 2 spot in the order, Zobrist scored 15 runs with 10 extra-base hits in 11 games. 

2014 – San Francisco Giants acquire RHP Jake Peavy

• The Deal: Traded by the Red Sox for minor league LHP Edwin Escobar and RHP Heath Hembree. 
• Deadline impact:  With Matt Cain out for season, he found a fresh start in the Bay Area -- going 6-4 with a 2.17 ERA after going 1-9 with a 4.72 ERA in Boston. 
• Postseason moment: After Madison Bumgarner pitched the Giants past Pittsburgh in the wild-card game, Peavy made their extended run a reality by beating Stephen Strasburg in Game 1 of the NLDS at Washington. 

2013 – Boston Red Sox acquire Peavy

• The Deal: Traded by the Chicago White Sox as part of a three-team, six-player deal that sent Jose Iglesias to the Tigers and Avisail Garcia to the White Sox. 
• Deadline impact: Peavy went 4-1 with a 4.10 ERA in 10 starts. 
• Postseason moment: Gave up one run in 5 2/3 innings of the decisive Game 4 of the AL Division Series against Tampa Bay. Also: Purchased the duck boat he rode on in the World Series parade.  

2012 – Giants acquire OF Hunter Pence

• The Deal: Traded by the Philadelphia Phillies for C Tommy Joseph, RHP Seth Rosin and OF Nate Schierholtz. 
• Deadline impact:  The Giants went on a 38-21 run after his arrival. 
• Postseason moment: Trailing the Cincinnati Reds 2-0 in the NLDS, Pence's pregame speech before Game 3 ignited an epic comeback series win. He would later score the go-ahead run in a 2-0 win in Game 3 of the World Series. 

Gallery: MLB trade deadline tracker