The worst-to-first turnaround is a baseball rarity.

Before the American League and National League were split into divisions in 1969, no team ever went from the worst record in its league one year to the best record the next.

Even after the 1969 reorganization, it took until 1990-91 for the first team to make the worst-to-first turnaround in its division. It has now happened 13 times in all, aided somewhat by the expansion to six divisions in 1994.

Here is a look at the teams that have successfully completed the one-year turnaround from worst to first.

2015-16 Red Sox
The Red Sox won 93 games in 2016, besting both the Orioles and Blue Jays by four games to win the American League East. Boston's win total marked a 15-game improvement on its 78-84 record from '15, which resulted in a last-place finish.

The Red Sox signed ace starter David Price, saw right-hander Rick Porcello turn into an AL Cy Young Award winner and experienced the meteoric rise of outfielder Mookie Betts, propelling Boston to the pinnacle of the AL East.

2014-15 Rangers
The Rangers won the AL West by two games in '15 despite going the entire season without their ace, Yu Darvish, who underwent Tommy John surgery in March 2015 and missed out on Texas' title run.

Yovani Gallardo, acquired via trade from the Brewers during the offseason, picked up the slack, going 13-11 with a 3.42 ERA. Mitch Moreland enjoyed a breakout season, and the Rangers finished third in the AL in runs scored en route to winning their first division title since 2011. They went from 67 wins to 88.

2012-13 Red Sox
The Red Sox unloaded Adrián González, Carl Crawford and Josh Beckett in a trade with the Dodgers in August 2012, finished in last place, and then proceeded to win the World Series one year later. It was quite a couple of months for then-general manager Ben Cherington, who signed Mike Napoli, Shane Victorino and Koji Uehara, and hired manager John Farrell that offseason.

The moves paid off as Boston led MLB in runs scored and Farrell's pitching staff rebounded, culminating in an AL East title and World Series championship. The Red Sox went from 69 wins to 97.

2010-11 D-backs
The D-backs are the only team in history to go from worst to first three times.

The team's roster didn't change much from 2010-11, but breakout seasons from Daniel Hudson (16-12, 3.49 ERA) and Ian Kennedy (21-4, 2.88 ERA), and the emergence of Josh Collmenter (10-10, 3.38) helped turn things around in a hurry. Justin Upton and Miguel Montero powered the D-backs' offense to the fourth-most runs scored in the NL. The club enjoyed a 29-game improvement in '11 to capture the NL West crown at 94-68.

2007-08 Rays
The 2008 Rays, under manager Joe Maddon, won 97 games and the AL pennant before losing to the Phillies in the World Series. Tampa Bay captured the AL East title for the first time in team history, after it had finished in last place nine times in its first 10 years.

The improbable reversal, following a 96-loss season, was made possible by AL Rookie of the Year Award winner Evan Longoria, who hit .272 with 27 home runs and 85 RBIs. Scott Kazmir and James Shields anchored a pitching staff that improved from the worst ERA in the AL in '07 to the second-best in '08.

2006-07 D-backs
The D-backs finished 2006 tied for last place in the NL West at 76-86. Arizona went 90-72 in 2007, winning the division by a half-game over Colorado, marking the second time in MLB history two teams went from worst to first in the same year.

With an offense that ranked 14th in the NL in runs scored, the D-backs rode ace Brandon Webb (18-10, 3.01 ERA) to the top of the standings, while Jose Valverde's MLB-leading 47 saves helped the club win 32 one-run games.

2006-07 Cubs
The Cubs rebounded after a 96-loss season in '06 by winning 90 games in '07. An overhauled roster that included free-agent additions Alfonso Soriano, Ted Lilly and Mark DeRosa, as well as a new manager in Lou Piniella, guided Chicago to the NL Central title in 2007. The Cubs were 22-31 on June 2 before surging late and winning the division by two games in the season's final week.

Piniella's key move was sending Carlos Marmol to the bullpen, where he thrived in a late-inning role, going 5-1 with a 1.43 ERA in 59 appearances.

1998-99 D-backs
Arizona entered MLB in 1998 as an expansion team, finishing in last place in the NL West with 97 losses. A year later, the D-backs completed one of the most dramatic turnarounds in MLB history, racking up 100 victories and capturing the division title by 14 games.

D-backs general manager Joe Garagiola Jr. signed Randy Johnson, who won his first of four straight NL Cy Young Awards in '99 by going 17-9 with a 2.48 ERA. Garagiola also added Luis Gonzalez and Steve Finley, who helped lead the way for a revamped Arizona offense that vaulted to the top of the NL in runs scored.

1997-98 Padres
The '97 Padres had the offense to compete for a division title. With outfielders Tony Gwynn, Steve Finley and Greg Vaughn, and Ken Caminiti at third, San Diego scored the second-most runs in the NL.

In '98, the Padres paired their talented offense with a new ace in Kevin Brown, who went 18-7 with a 2.38 ERA. Trevor Hoffman locked down a career-high 53 saves to help the club win the NL West by 9 1/2 games, going from 76 wins to 98 in one year.

1996-97 Giants
Newly promoted general manager Brian Sabean wasted no time improving a Giants team that finished last in the NL West at 68-94 in 1996.

What was previously the Barry Bonds show in San Francisco quickly became a balanced and potent lineup with the trade acquisitions of J.T. Snow and Jeff Kent, who combined for 57 home runs and 225 RBIs in '97 to help the Giants win 90 games and take the NL West crown.

1992-93 Phillies
The Phillies experienced a 27-win improvement from 1992-93, largely in part to veteran leadership and offensive firepower. They went 97-65 to capture the NL East.

Center fielder Lenny Dykstra hit .305 with 19 home runs and 66 RBIs, along with 37 stolen bases, while catcher Darren Daulton and first baseman John Kruk combined for 38 homers and 190 RBIs as Philadelphia led the NL in runs scored.

1990-91 Twins
After not having a single team ever go from worst to first, MLB saw two clubs do so in the same season. The Twins went from 74-88 and a last-place finish in the AL West to winning the division and the World Series -- over the Braves -- a year later. They improved by 21 games, going 95-67.

The additions of designated hitter Chili Davis, right-hander Jack Morris and 1991 Rookie of the Year Chuck Knoblauch helped Minnesota execute a turnaround season.

1990-91 Braves
The 1991 Braves collected 94 wins, a 29-game improvement from the prior season. The free-agent signing of Terry Pendleton fueled the revival. The third baseman hit a National League-best .319, along with 22 home runs and 86 RBIs, en route to winning the NL MVP Award.

Blossoming young arms Tom Glavine, John Smoltz and Steve Avery helped Atlanta's pitching staff record the NL's third-lowest ERA, just one year after finishing last in the league in the same category.

Atlanta's resurgence sparked a stretch of 14 straight division titles, which stands as the longest streak in MLB history.