Major League Baseball's 2018 regular season is now a month old. While all statistics still fall under the small-sample umbrella, that doesn't mean we can't begin looking at the bigger picture. For example, which teams have gained and relinquished the most ground in their hunt for the postseason as compared to their preseason projections?

To provide the top five gainers and losers in that category, let's turn to FanGraphs' playoff odds.

Top gainers

Arizona Diamondbacks

Preseason: 24 percent

Current: 58.9 percent

Net: 34.9 percentage points

The D-Backs entered Sunday with the largest division lead in baseball. In fact, their five-game cushion is larger than four of the other five division leaders' margin over the third-place team. The Diamondbacks have started 19-7 despite losing starting pitcher Taijuan Walker to Tommy John surgery, receiving minimal contribution from third baseman Jake Lamb, and having yet to see right fielder Steven Souza Jr. make his regular-season debut. Credit the pitching staff, and especially the bullpen -- just one Arizona reliever with multiple appearances has an ERA over 2.00, and that's closer Brad Boxberger at 2.70. Impressive.

Boston Red Sox

Preseason: 84.2 percent

Current: 96.7 percent

Net: 12.5 percentage points

Unlike the Diamondbacks, the Red Sox entered spring expected to make the postseason. As such, their 19-7 start afforded them only so much room to improve upon their preseason odds. Mitch Moreland, Xander Bogaerts and Hanley Ramirez have served as unlikely breadwinners for the Boston lineup. Meanwhile, Chris Sale, David Price and Rick Porcello are living up to their potential as a vaunted one-two-three punch at the top of the rotation. The Red Sox could get second baseman Dustin Pedroia and reliever Tyler Thornburg back from injury in May.

Atlanta Braves

Preseason: 3.2 percent

Current: 11.3 percent

Net: 8.1 percentage points

Even before the Braves promoted Ronald Acuña Jr., they had a lineup stocked with heretofore good performers. Only one of their eight top recipients in plate appearances has an OPS+ below 100 -- and that's all-world center fielder Ender Inciarte. Even waiver-wire bait like Ryan Flaherty and Preston Tucker have held their own. The Braves will presumably promote José Bautista sooner than later in an attempt to add more punch. The bigger area of concern might be the bullpen, however, as three of the Braves' top relief arms (Arodys Vizcaino, A.J. Minter, and Sam Freeman) have issued more than a walk every other inning. The Braves are probably still a year off from making a serious run at October, but this is the best team SunTrust Park has seen.

Los Angeles Angels

Preseason: 27.1 percent

Current: 34.4 percent

Net: 7.3 percentage points

Mike Trout has been Mike Trout, Shohei Ohtani has been a revelation, and Albert Pujols is closing in on 3,000 hits. Those have been the top storylines from the Angels' first month. The key to the Angels' season remains the rotation and how healthy it can stay over the long haul. Thus far, Los Angeles has received 11 starts combined from Garrett Richards and Tyler Skaggs. That's a good sign. Who knows what the future brings, but the Angels are showing why many picked them to claim a wild card spot.

New York Mets

Preseason: 44.9 percent

Current: 51.3 percent

Net: 6.4 percentage points

Similar to the Angels in that the Mets' playoff hopes come down to their rotation's health. Jacob deGrom and Noah Syndergaard have each been brilliant, and adding Jason Vargas to the mix should help. Keep an eye on the lineup, too. First baseman Adrian Gonzalez isn't hitting, which could prompt New York to move Jay Bruce to the cold corner to get Brandon Nimmo more playing time. The Mets have to assume Yoenis Céspedes will get going soon, too.

Top losers

Washington Nationals

Preseason: 89.3 percent

Current: 67.8 percent

Net: -21.5 percentage points

Oy. The Nationals have their share of injuries -- second baseman Daniel Murphy and third baseman Anthony Rendon each received MVP consideration last season and have appeared in 14 games combined; center fielder Adam Eaton has also missed significant time already -- but a lot else has gone wrong here. Ryan Zimmerman and Michael A. Taylor have failed to build upon impressive 2017 campaigns, while the bullpen has looked as sieve-like as the one the Nats trotted out there around this time last season. There's ample time to get things right and sufficient reason to believe the Nationals will do just that. But they will be fighting from underneath given how well the Mets and Philadelphia Phillies have performed this year.

Minnesota Twins

Preseason: 28.7 percent

Current: 13.3 percent

Net: -15.4 percentage points

The Twins were as busy as any team during the winter, adding the likes of Logan Morrison, Jake Odorizzi, Lance Lynn and Fernando Rodney to a roster that was good enough to make the wild card game last fall. Yet Minnesota has gotten off to a rotten start, recently punctuated by an eight-game losing streak. Morrison has struggled; Rodney is in danger of losing his closer's job; and Odorizzi and Lynn have yielded 43 hits, 29 runs, and nine homers in 44 ⅔ innings. Add in Byron Buxton's fractured toe, and nothing is going as planned.

San Francisco Giants

Preseason: 23.9 percent

Current: 12 percent

Net: -11.9 percentage points

Speaking of which, the Giants can't catch a break of their own. Madison Bumgarner is probably a month away from rejoining the rotation, while Mark Melancon, Joe Panik, Hunter Pence and even Mac Williamson -- whose recent power surge inspired hope he was breaking out -- are all on the disabled list. To their credit, the Giants have stuck around .500. But, with the Diamondbacks jumping out to a quick, comfy lead in the division, San Francisco has seen its playoff odds drop by half. The Giants need to get healthy sooner than later to make a real run.

Los Angeles Dodgers

Preseason: 93 percent

Current: 83.1 percent

Net: -10.9 percentage points

The Dodgers' plight is similar to the Giants' in that injuries are at least partially to blame. Justin Turner hasn't yet played this season, and he's been joined on the DL by Rich Hill, Logan Forsythe and Tom Koehler -- don't laugh, Koehler was one of the Dodgers' biggest (read: only) offseason additions. Presumably the Dodgers will start getting better production from some of their lagging contributors (Chris Taylor, Corey Seager and Yasiel Puig included). That, plus the Dodgers' ridiculous depth -- Andrew Toles would be starting on most teams -- makes it tough to put too much water in Los Angeles' poor start. Still, it's fair to write this has been a rough start.

Texas Rangers

Preseason: 7.7 percent

Current: 1.9 percent

Net: -5.8 percentage points

The Rangers making this list despite entering the year with modest-at-best playoff hopes speaks to how poorly things have gone for them. The Rangers are without Elvis Andrus, Adrián Beltré and Rougned Odor -- and have seen both Matt Moore and Martin Pérez struggle to tap into their promise. The answer for so many of these teams is it's early. For the Rangers? With the quality of teams elsewhere in the American League West? It might already be late -- to the point where it might already be time to start pondering who goes when Texas begins a sell-off.