Top 6 most improved teams this offseason

Can a team lose a Hall of Fame-level player to retirement after a vintage season and get better the next season?
The Red Sox suggest the answer is yes.
As great as David Ortiz has been, all the way through a 38-home run performance in his age-40 season, he was only the fourth most productive member of John Farrell's lineup in 2016. Mookie Betts, Dustin Pedroia and Jackie Bradley Jr. were all bigger contributors, measured by WAR. So losing Ortiz may not be as big of a blow in reality.
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Credit Red Sox president of baseball operations Dave Dombrowski for pulling off one of the few moves that would overshadow Ortiz's retirement -- the trade for Chris Sale at the Winter Meetings.
In an offseason when the talent on the free-agent market was limited, dealing Yoán Moncada and three other prospects to the White Sox for the electrifying lefty was a masterstroke.
Sale joined defending American League Cy Young Award winner Rick Porcello and David Price to give Boston a front-of-the-rotation combination that potentially could supplant the Cubs' trio of Jon Lester, Kyle Hendricks and Jake Arrieta to be the best in the Major Leagues. Sale hasn't won his own Cy Young Award, but he has finished in the top six in AL balloting each of the past five years -- a streak that only Clayton Kershaw tops in the National League.
Expect Sale to cherish the chance to pitch for a team that will almost certainly give him his first crack at experiencing postseason baseball. It's a bonus that the Red Sox train near his home in Naples, Fla.

Dombrowski made a couple of other nice moves -- adding free-agent first baseman Mitch Moreland to upgrade the infield defense (and take many of the at-bats vacated by Ortiz) and trading for Tyler Thornburg, who will serve as a setup man for Craig Kimbrel. No team improved more this offseason than Boston.
Here's a ranking of the other teams that got significantly better:
2. Indians
This was a weak free-agent market and, surprisingly, more than half of the top players re-signed with their teams (Yoenis Céspedes, Mets; Kenley Jansen, Rich Hill and Justin Turner, Dodgers; Mark Trumbo, Orioles; José Bautista, Blue Jays; Jeremy Hellickson, Phillies; and Iván Nova, Pirates). Edwin Encarnación was viewed as being out of Cleveland's price range, but the Tribe got him for $65 million over three years, which was $15 million less than he turned down on an extension offer from the Blue Jays.

Encarnacion, who has had a .912 OPS while hitting 193 home runs over the past five years, is an upgrade over stopgap first baseman Mike Napoli, who struggled through the Indians' ride to Game 7 of the World Series (.173, one homer in 52 postseason at-bats). Encarnacion is not Anthony Rizzo defensively, but he makes routine plays and his arrival moves Carlos Santana back to the DH role, where he belongs.
In an otherwise a quiet offseason in Cleveland, the health of left fielder Michael Brantley, catcher Yan Gomes and starters Carlos Carrasco and Danny Salazar could be huge in '17.
3. Mariners
The guess here is that the trade for shortstop Jean Segura will prove even more significant than upgrading the back of the rotation or the outfield defense. Segura, playing second base, was a monster last season for the disappointing D-backs. He had a 5.0 fWAR, which could make him a top five shortstop if he maintains that level, while moving back to the position he played with the Brewers and Angels. Segura will join newly acquired left fielder Jarrod Dyson in hitting in front of Robinson Canó, Nelson Cruz and Kyle Seager, making him a good bet to build off the career-high 102 runs he scored last year.

Dyson and right fielder Mitch Haniger (acquired alongside Segura in a trade for Taijuan Walker and Ketel Marte) will flank center fielder Leonys Martin in an extremely athletic outfield, and the Mariners will look to newcomers Drew Smyly and Yovani Gallardo to fill out the rotation behind Félix Hernández, James Paxton and Hisashi Iwakuma. Carlos Ruiz, acquired from the Dodgers, provides experience behind No. 1 catcher Mike Zunino.
4. Cardinals
Along with Lester, Dexter Fowler played a huge role for the Cubs as they went from being a rebuilding team to baseball's best team over the past two years. St. Louis paid heavily ($82.5 million, five years) to land him, and it was exactly the kind of move it needed to make.

Scoring runs wasn't a problem for the Cardinals in '16; catching the ball was. Fowler steps into center field, allowing Randal Grichuk to move to left field, where he'll be one of the top fielders after being only average in center. Fowler will also take over as the leadoff role, letting Matt Carpenter focus more on driving the ball.
Free-agent left-hander Brett Cecil lessens the load on the heavily worked Kevin Siegrist, upgrading the bullpen in front of Seunghwan Oh. The Cardinals also may have made an addition-by-subtraction move in trading the often-injured Jaime García to the Braves. He was a 13-game winner in both his age-23 and -24 seasons, but that was back in '10 and '11. He made 30 starts and delivered a 4.67 ERA last season.
5. Astros
Rather than paying heavily to deal for a front-of-the-rotation starter, Jeff Luhnow signed Charlie Morton as a depth piece and worked to improve other parts of his team. Catcher Brian McCann (replacing departing free agent Jason Castro) and outfielders Carlos Beltrán, Josh Reddick and Norichika Aoki were added to the lineup built around explosive young hitters.

Beltran represents an especially shrewd signing as he could be this year's Ortiz -- a 30-homer, 100-RBI player in his age-40 season. He's as professional as it gets, too, which will help as the Astros try to win their first division title since '01.
6. Giants
You know you're in trouble when even Bruce Bochy can't fix your bullpen. Mark Melancon isn't as flashy as Aroldis Chapman or Jansen, but he's been just as reliable, which is why San Francisco signed him for $62 million over four years. The Giants might have been near the top of these rankings if they had added a third baseman like Todd Frazier or an impact outfielder like Fowler.

Honorable mentions: Nationals, Braves, Rockies
Adam Eaton has never been an All-Star, but he has twice been the centerpiece of a significant trade, going from the D-backs to the White Sox after '13 and now to the Nats for Lucas Giolito, Reynaldo López and Dane Dunning. Consider the upcoming season a referendum on his ability to deliver when it matters. The Nats are gambling that Derek Norris' pitch-framing will offset the loss of Wilson Ramos as their primary catcher. The Braves are taking risks on Garcia, Bartolo Colon and R.A. Dickey as they buy time to develop their stable of pitching prospects. Sean Rodríguez should be a useful utility player. Ian Desmond makes the Rockies' already deep lineup more balanced.