MORE: Watch live MLB games all season long on fuboTV (7-day free trial)2018 Red Sox, Nathan EovaldiThe deal: July 25, traded from Rays to Red Sox for lefty pither Jalen BeeksThoughts: Eovaldi was long the guy with the triple-digit fastball who seemed to be injured or slightly more ineffective than his stuff said he should be. But he was outstanding with the Red Sox, rolling up a 2.88 FIP in 12 games (11 starts) during the regular season, and then he became a Boston legend in the postseason. In the ALDS, he shut down the Yankees, allowing just one run on five hits in seven innings. In the ALCS, he started Game 3 and allowed two runs in six innings, and then he came back to throw a scoreless relief inning in Game 5. And then, in the World Series, Eovaldi threw shutout relief innings in both Games 1 and 2, and tossed six shutout frames in Game 3, the epic 7-hour, 20-minute contest that finally ended when Max Muncy popped a homer off Eovaldi to open the 18th inning.Special mention to Steve Pearce, who hit seven homers with a .901 OPS after the Sox picked him up in late June from the Blue Jays, then wound up winning World Series MVP honors after batting .333 with three homers and eight RBIs in the five-game series. 2017 Astros, Justin VerlanderThe deal: Aug. 31, traded from the Tigers to Astros for three prospects: Daz Cameron, Franklin Perez and Jake Rogers. The Tigers sent prospect Juan Ramirez to the Astros in mid-October to compete the deal. (Worth noting that the Aug. 31 deadline no longer exists; teams used to be able to place players on waivers after the July 31 non-waiver deadline and still deal them. Starting in 2019, though, all trades, with no exceptions, must happen by July 31.)Thoughts: This worked out better than the Astros could have imagined. Verlander made five regular-season starts for his new club and fashioned a 1.06 ERA (not a typo). In the postseason, he went at least six innings in each of his five starts — including a 13-strikeout complete game against the Yankees in the ALCS — and made one relief appearance. The Astros, of course, outlasted the Dodgers in a seven-game classic, and Verlander finished his postseason run with a 2.21 ERA in 36 2/3 innings. And that performance wasn’t a fluke. Verlander finished second in the AL Cy Young voting in 2018 — 2.52 ERA, 6.2 bWAR, 7.84 K/BB — and has pitched well enough in 2019 to earn the starting nod for the AL in the All-Star Game. 2016 Cubs, Aroldis ChapmanThe deal: July 25, traded from the Yankees to Cubs for Gleyber Torres, Adam Warren, Billy McKinney and Rashad CrawfordThoughts: Chapman had been suspended for 30 games that season for a domestic violence incident that happened at his Miami home the previous October. The Cubs, desperate for bullpen help with a team otherwise equipped to win the World Series for the first time in 108 years, dealt for Chapman anyway. He was really good in the regular season (1.01 ERA, 16 saves) and just OK in the postseason, rolling up a 3.45 ERA and blowing saves in three of his seven opportunities, including in the eighth inning of Game 7. But the Cubs did, of course, wind up winning the World Series despite Chapman’s final-game hiccup.But here’s the thing: The Cubs won the World Series, but the cost was steep. The current front office lost any sort of claim that character matters when they traded for Chapman, and they also gave up Gleyber Torres, who could be one of the best players in baseball for the next decade, at least. Torres had 24 homers and a 2.9 bWAR in 123 games for the Yankees last year, and in 94 games this season he has 20 homers and a 2.6 bWAR. 2015 Royals, Johnny CuetoThe deal: July 26, traded from the Reds to Royals for Brandon Finnegan, John Lamb and Cody ReedThoughts: The early returns weren’t great for the Royals. Cueto, who finished second in the NL Cy Young race in 2014 and had a 2.62 ERA in 19 starts for Cincy in 2015 at the time of the trade, was wildly inconsistent early in his Kansas City tenure. He posted a 1.13 ERA in his first three starts with his new team, but then a 9.57 ERA in his next five starts. He was seen as a giant wild card in the K.C. rotation heading into October, and that proved true. He was OK in his first start (six innings, four runs) and then brilliant in a winner-take-all Game 5 ALDS start against Houston (eight innings, two runs). In Toronto during the ALCS, though, he lasted just two innings and gave up eight runs. His start in Game 2 of the World Series against the Mets was important, not just because it’s the World Series but because the Royals had used seven pitchers in their 14-inning Game 1 win. Cueto was brilliant again, allowing just two hits and one walk in a complete-game gem the Royals won 7-1. Special shoutout to Ben Zobrist, too. He was K.C.’s other big pickup, and he was outstanding, too. He hit .284 with a 120 OPS+ in 59 regular-season games, then .333 in the ALDS, .320 in the ALCS (with two homers) and .261 (with five runs in five games) in the World Series win. 2014 Giants, Jake PeavyThe deal: July 24, traded from the Red Sox to Giants for Edwin Escobar and Heath HembreeThoughts: Peavy’s Cy Young-candidate days were in the past at this point in his career, and he’d been pretty blah for the Red Sox in the first half of 2014 (4.72 ERA in 20 starts). With the Giants, though, he cut down on the walks and found the type of success he hadn’t seen much over the past few seasons. In his dozen regular-season starts for San Francisco, Peavy had a 2.17 ERA, and he didn’t allow a run in his NLDS start against the Nationals, shutting out the 96-win team from D.C. through 5 2/3 innings. His final three playoff starts weren’t great, but the Giants had Madison Bumgarner so not much else mattered. Even if you think your favorite team might have the necessary pieces to win the World Series, you’ll have to forgive your favorite team’s front office if they still decide to make an impact move or two before the July 31 trade deadline. With that deadline approaching, here’s a look at the past five World Series champs and the trade acquisition that made the biggest impact on their push to the postseason and, finally, to a championship.