The current format of having two Wild Card teams from each league provides opportunities, and the D-backs, Rockies and Twins each took advantage as they tasted surprising success in 2017.
Those three clubs, which each finished well below .500 the year before, improved by a combined 62 victories. All three qualified for the postseason, snapping droughts of at least five seasons.
With Spring Training fast approaching, it's worth wondering who might pull off a similar one-year jump in 2018.
Here is a look at four candidates coming off sub-.500 campaigns, and a suggestion for what each can still do on the free-agent market to further help its chances. (Clubs listed in descending order of 2017 record).
Los Angeles Angels
2017: 80-82, second place in American League West, five games out of AL Wild Card berth
2018 projection, via FanGraphs: 88-74
In Michael Trout's six full big league seasons, the Angels have gone to the postseason once, suffering an AL Division Series sweep at the hands of the Royals in 2014. But general manager Billy Eppler has done quite a bit to fix that. Landing two-way star Shohei Ohtani from Japan was perhaps the biggest move of the offseason, with potential implications not only for the rotation, but also the designated hitter spot. The 23-year-old ranks No. 1 on MLB Pipeline's list of baseball's Top 100 Prospects. The Halos also retained slugging left fielder Justin Upton (a late-2017 trade pickup) by signing him to a contact extension, traded for second baseman Ian Kinsler and signed free-agent third baseman Zack Cozart. Combine those additions with a full season from Trout and better health from an injury-riddled rotation, and the Angels certainly have a shot at their first playoff win since '09.
The next step: There are no shortage of starting-pitching options here, but each of them has health-related question marks, and there is no such thing as too much depth in this area. With that in mind, either Alex Cobb or Lance Lynn would help solidify the group. R.A. Dickey isn't as big of a name at this point, but the knuckleballer would serve as a great insurance policy due to his reliable ability to eat innings.
New York Mets
2017: 70-92, fourth place in National League East, 17 games out of NL Wild Card berth
2018 projection, via FanGraphs: 80-82
Coming off back-to-back postseason appearances, including a trip to the 2015 World Series, the Mets saw just about everything go wrong last season. Much of their offseason has been spent retaining or bringing back familiar players (Jay Bruce, Jose Reyes), but Anthony Swarzak was an underrated bullpen addition, and new manager Mickey Callaway could be a positive influence, especially on the rotation. Still, much will depend on how much playing time the Mets get from the likes of Yoenis Cespedes (81 games in 2017), Noah Syndergaard (seven starts) and Jeurys Familia (26 games), not to mention Michael Conforto, who is recovering from shoulder surgery.

The next step: New Jersey native Todd Frazier seems like an ideal fit here, as a source of right-handed power and stellar defense at the hot corner. New York could then use a combination of Asdrubal Cabrera, Wilmer Flores and Reyes at second base, with Frazier also an option to pair with the left-handed Dominic Smith and Adrian Gonzalez at first.
Philadelphia Phillies
2017: 66-96, fifth place in NL East, 21 games out of NL Wild Card berth
2018 projection, via FanGraphs: 75-87
Philadelphia clearly is trending up after a six-season postseason drought, but the issue is whether that process is happening quickly enough to get the team back to October this year. Working in Philly's favor are the signing of steady first baseman Carlos Santana, as well as relievers Pat Neshek and Tommy Hunter. But just as important is the degree to which the young core is ready to deliver. If Rhys Hoskins authors a worthy followup to his sensational debut, and shortstop J.P. Crawford, catcher Jorge Alfaro, pitcher Vince Velasquez and others take steps forward, it's not difficult to envision the bright future arriving sooner rather than later.

The next step: The rotation remains young and mostly unproven, and the Phillies have the resources to go after an accomplished veteran to decrease their reliance on those developing arms. Darvish and Jacob Arrieta are lingering on the market, and either would bring a significant upgrade over the in-house options.
San Francisco Giants
2017: 64-98, fifth place in NL West, 23 games out of NL Wild Card berth
2018 projection, via FanGraphs: 84-78
The run of three World Series championships in five seasons from 2010-14 -- or even the '16 postseason trip -- seemed like an ancient history last summer, as the Giants sunk to the worst record in the NL. Still, they won five more games than the '16 Twins. San Francisco certainly views its window as remaining open, having embarked upon a risky-but-ambitious offseason. Evan Longoria, Andrew McCutchen and Austin Jackson all addressed clear needs, and will spur an offense that hit 23 fewer home runs than any other club. A full season from Madison Bumgarner would provide an obvious boost to the rotation, which also could use a rebound year from Johnny Cueto.
The next step: The Giants are in go-for-it mode, but they haven't really addressed a bullpen that was far from reliable in 2017. With Mark Melancon, Sam Dyson and Tommy John surgery rehabber Will Smith all carrying question marks, why not take a shot on Greg Holland, who saved 41 games last year for the Rockies?