In the one month since the All-Star break, there have been some major changes to MLB’s postseason picture.

While many pre-break contenders have solidified their standing, others have fallen off -- opening the door for some surprise teams to get back into the mix. 

Using FanGraphs’ playoff odds, here are the 12 teams -- the six biggest risers and six biggest fallers -- whose postseason chances have shifted the most since the second half got underway. (All stats below, including odds, are through Friday.)

Biggest risers

1) Cubs: +45.3 (9.5% to 54.8%)
The Cubs were on the road toward a Trade Deadline sale after starting off 43-50 this season. However, the club ripped off 10 wins in an 11-game span from July 18-29 and ended up buying at the Deadline, acquiring third baseman Jeimer Candelario (slashing .459/.512/.676 with the Cubs) from the Nationals while retaining Cody Bellinger, who has hit .407/.446/.737 with 11 homers in his past 31 games. Overall, the North Siders have gone 18-9 with MLB’s highest-scoring offense (6.59 runs per game) and second-best run differential (+44) since the break.

2) Phillies: +36.6 (54.2% to 90.8%)
The 2022 NL champions took some time to get going this season, starting off 25-32. But they’ve posted a .667 winning percentage over their past 60 games and are now heavy favorites to reach the playoffs, despite having little chance to overtake the first-place Braves in the NL East. The Phils were a half-game out in the NL Wild Card race when the second half began, but they’ve moved into the top spot on the strength of a 17-11 record -- with MLB’s third-best run differential (+34) -- since the break. Philadelphia is even beginning to see more production from free-agent addition Trea Turner, who has recorded a .406 average with eight extra-base hits (two homers) during his eight-game hitting streak.

3) Twins: +28.6 (57.6% to 86.2%)
Minnesota entered the All-Star break a half-game behind the Guardians in the AL Central with a 45-46 record, but has gone 15-12 in the second half to reclaim first place. Every other AL Central team is six games below .500 or worse on the season besides the Twins (61-58), which explains why their playoff odds are so high even though they are tied for only the seventh-most wins in the AL.

4) Astros: +22.2 (66.3% to 88.5%)
The reigning World Series champs haven’t spent a single day in sole possession of first place in the AL West this season, but they’ve gone 18-9 since the break and remain within striking distance of the first-place Rangers with less than eight weeks to go. The returns of Yordan Alvarez and Jose Altuve from the injured list in late July and the stunning trade for Justin Verlander at the Deadline gave Houston some much needed reinforcements for the stretch run.

T-5) Rangers: +21.1 (68.4% to 89.5%)
Every time the Rangers have started to fade, they’ve been able to respond with a strong stretch to keep the Astros at bay in the AL West. Their latest surge? A 10-1 start to August, following a 2-7 slump to close out July. And after their front office put together a splashy Deadline (Max Scherzer, Jordan Montgomery, Austin Hedges) to replace some of the players they’ve lost to injuries (Jacob deGrom, Nathan Eovaldi, Jonah Heim), the Rangers appear well equipped to claim either the division title or a Wild Card spot. It would be Texas' first postseason appearance since 2016.

T-5) Mariners: +21.1 (22.5% to 43.6%)
The Mariners have been one of baseball’s hottest team, winning eight straight before a 1-0 loss on Saturday and 13 of their past 16 to vault back into the playoff race. All-Star center fielder Julio Rodríguez has been at the center of the club’s resurgence on offense, hitting .349 with five homers, seven doubles, 15 RBIs and a 1.076 OPS in his past 15 games. What was a 5 1/2-game deficit for the M’s in the AL Wild Card standings entering play on July 25 has been trimmed to a half-game.

Biggest fallers

1) D-backs: -51.0 (64.4% to 13.4%)
Unlike some of this year's other surprise contenders such as the O's and Rangers, the D-backs haven't been able to sustain their early success. With rookie sensation Corbin Carroll hitting a wall (.686 OPS in second half) and the team's rotation lacking depth behind Zac Gallen and Merrill Kelly, Arizona has gone 8-25 since it reached a season-high 16 games above .500 on July 1. The D-backs won their first August game on Saturday and are one game below .500 on the season, three games out of an NL Wild Card spot.

2) Yankees: -46.7 (55.6% to 8.9%)
The Yankees’ season took a turn for the worse when Aaron Judge suffered a toe injury on June 3 that knocked him out for 42 games, and the reigning AL MVP’s return hasn’t been enough to rejuvenate the spiraling club amid a myriad of other issues. New York is 11-15 in the second half, averaging only 4.12 runs per game in that span, and just lost two out of three to a White Sox team that was one of this year’s most active sellers. While the Bronx Bombers are still three games above .500, they’re in last place in the AL East and four games out in the AL Wild Card race.

3) Marlins: -40.1 (74.4% to 34.3%)
Miami reached a season-high 14 games above .500 on the final day of the first half, but the time off seemed to stall the club’s momentum. The Marlins, who haven’t made the postseason in a non-shortened campaign since their 2003 World Series title, lost their first eight games after the All-Star break and are 8-18 in the second half -- MLB’s second-worst record behind the D-backs’ 6-20 mark. Averaging just 3.52 runs per game, Miami has been outscored by 38 runs since the break and is now a half-game out in the NL Wild Card standings.

4) Guardians: -28.5 (40.6% to 12.1%)
After starting off the season 32-38, the Guardians closed the first half on a 13-7 run and went into the All-Star break in first place in the AL Central with a half-game lead over the Twins. However, Cleveland has gone 11-17 in the second half, falling 4 1/2 games behind Minnesota. The team also sold at the Deadline, trading away Aaron Civale, Josh Bell and Amed Rosario.

5) Red Sox: -13.9 (29.7% to 15.8%)
The Red Sox haven’t played poorly since the All-Star break (13-13), but they’re practically in the same spot as they were when the second half began. Boston came out of the break facing an 8 1/2-game deficit in the AL East and a two-game deficit in the AL Wild Card standings. Nearly a month later, they’re 11 games out in the division and three games out in the Wild Card race. Perhaps the return of Chris Sale, who struck out seven and allowed only one hit over 4 2/3 innings on Friday in his first start since June 1, will give the Red Sox enough pitching to make a run.

6) Mets: -13.3 (14.5% to 1.2%)
The Mets had the third-highest playoff odds in the NL prior to Opening Day, but they went 42-48 in the first half. Any hope they had of getting back into the race evaporated when they opted to sell at the Deadline, trading away Verlander, Scherzer, David Robertson, Mark Canha and Tommy Pham. It's only gotten worse for the club, as New York has gone 2-10 since the Deadline and is now 52-65, the fourth-worst record in the NL.