Statheads know that it usually takes roughly 70 games for baseball results to really start meaning something. On the first day of May a year ago, the New York Mets were 17-9 and the Los Angeles Dodgers were 12-16. Needless to say, both these teams’ fortunes would change: The Mets immediately collapsed into oblivion; the Dodgers went 80-55 the rest of the way and made the World Series. So the sensible move would be to sit tight and ignore the standings for a few more weeks.

But we obviously aren’t going to do that — it’s too much fun to speculate about which hot starts are for real. And MLB’s first full month had plenty of interesting results: As some favorites’ playoff chances have receded, other teams have put themselves in strong postseason position already. Here are the teams that have improved the most in our MLB Elo ratings since opening day:

MLB’s most improved teams since preseason MLB teams with the largest change in FiveThirtyEight’s Elo ratings between opening day and April 30, 2019 Elo Ratings change Team Division Record Preseason Current Elo Playoff odds Rangers AL West 14-13 1459 1473 +14 +4 Rays AL East 19-9 1525 1539 +13 +32 Twins AL Central 17-9 1508 1520 +13 +26 D-backs NL West 16-13 1497 1510 +12 +12 Cardinals NL Central 18-10 1525 1537 +12 +23 Mariners AL West 18-13 1491 1497 +7 +3 Blue Jays AL East 14-14 1482 1488 +6 +2 Cubs NL Central 14-12 1521 1527 +6 +6 Dodgers NL West 19-12 1562 1566 +4 +9 Phillies NL East 16-12 1519 1521 +2 +9 Sources: Baseball-Reference.com, Baseball Databank

We can break the most improved teams into a couple of groups. One features teams that were on the edge of contention before the season and whose hot starts solidified them as teams to be reckoned with in the playoff race. The other contains clubs who were not “supposed” to be this good (or even good at all) in the eyes of the preseason projections. These teams are in an interesting spot because their playoff odds are still low despite their promising showings. So how well they maintain their surprising performances will have a big effect on their decision-making around July’s trade deadline.

Playing themselves into contention

No team has improved its playoff odds more in April than the Tampa Bay Rays, who had a 42 percent shot at the postseason on opening day but as of Tuesday boasted a 74 percent chance to make the playoffs. Some of that is a byproduct of Boston’s poor start — the Red Sox had shed an MLB-high 39 points of playoff probability since starting the season — but the Rays are also a great example of a team that makes shrewd acquisitions and gets the most out of its talent. In addition to known commodities Tommy Pham, Kevin Kiermaier and Blake Snell, Tampa is also getting unexpectedly great performances out of infielders Yandy Diaz and Brandon Lowe, right fielder Austin Meadows and pitcher Tyler Glasnow. Some of that quartet’s early numbers are bound to revert to the mean, but Diaz, Lowe and Meadows all rank among the top 20 percent of hitters in exit velocity, and Glasnow has elite underlying indicators. Although the injury-plagued Yankees are the AL East favorites in our model, no team currently has better wild-card odds than Tampa Bay.

As we mentioned before the season, the Minnesota Twins figured to be right in the most precarious zone between making and missing the postseason. A few extra wins here or there, and the Twins’ playoff odds would increase massively; a few extra losses, and they might be left out in the October cold. So Minnesota has done itself a huge favor by getting off to a 17-10 start, which is third-best in baseball. Obvious star candidates such as Byron Buxton and Jose Berrios have played well, but the Twins’ hot April was fueled even more by breakout seasons from the likes of Jorge Polanco (162 adjusted on-base plus slugging), Eddie Rosario (130) and even catcher Mitch Garver (203). Minnesota’s rotation has huge questions beyond Berrios and Jake Odorizzi, but with the Indians’ talent advantage in the AL Central diminished relative to previous seasons, the Twins have played their way into what could be the division’s most interesting race in years.

The St. Louis Cardinals are a little different from the Rays and Twins because we basically listed them as co-favorites (with the Brewers and Cubs) in the NL Central during spring training. Still, with an 85-win projection on the heels of a three-year playoff drought, the Cards’ postseason fate was far from assured. The team’s hot start, however, has set St. Louis up with a 67 percent chance of making the playoffs as of Tuesday — 23 percentage points higher than it was before the season started. Prized offseason acquisition Paul Goldschmidt has been his usual self, while lineup mates Paul DeJong, Marcell Ozuna, Kolten Wong and Dexter Fowler have exploded for huge seasons so far. It’s fair to wonder how long some of that can last: At age 33, Fowler is a little old to suddenly emerge as a 5-win player, while DeJong has a .607 slugging percentage despite an average exit velocity in the bottom third of MLB. But by the same token, the Cardinals’ pitching is probably better than its current 25th-place ranking in wins above replacement, particularly once Carlos Martinez returns from injury this month. Whatever happens, St. Louis has given itself the early edge in a brutal division race.

We’re good! OK, now what?

The Texas Rangers got everybody’s attention over the weekend by blistering the Seattle Mariners by a combined score of 29-2 in back-to-back games. The Rangers are 14-14, but they also have a +9 run differential against a schedule that ranks second-toughest in baseball so far, according to the average Elo rating of its opponents. Texas wasn’t supposed to be competitive like this: They haven’t broken .500 since 2016, and they lost longtime franchise cornerstone Adrian Beltre to retirement over the offseason. But the team has seen a handful of pleasant surprises early on — starting with pitcher Mike Minor, who boasts the eighth-best adjusted earned run average (174) in the AL. Left fielder Joey Gallo has launched 10 home runs already, Elvis Andrus and Shin-Soo Choo have produced vintage seasons, and Danny Santana has recaptured the form that saw him vie for rookie of the year honors in 2014. But even with all that, Texas is still just third in the AL West, and our model gives it only a 7 percent chance of making the playoffs. In the race to the bottom for better picks, the Rangers were looking before the season like they might get a top-five selection in next summer’s MLB draft, but now their hot start might have them rethinking their rebuilding trajectory for the time being.

Similarly, the Arizona Diamondbacks seemed destined for a rebuild after trading Goldschmidt to the Cardinals and watching free agents such as Patrick Corbin walk during the winter. Yet those plans might need to be put on hold in light of the team’s 17-13 start. According to our model, the D-backs on Tuesday had a 35 percent chance to make the playoffs (up 12 percentage points from preseason) and are on track to win 83 games, which would actually be an improvement on last year’s record despite the offseason talent exodus. First baseman Christian Walker (151 OPS+) has come out of nowhere with a scorching start, Zack Greinke continues to pitch like an ace, and closer Greg Holland hasn’t yet allowed a run. Arizona has gotten strong performances up and down the lineup, including from the likes of David Peralta, Adam Jones, Ketel Marte, Eduardo Escobar, Nick Ahmed and Jarrod Dyson. The Dodgers look too good to realistically be chased down in the West, but the D-backs are still in the NL’s playoff race, however improbably.

The Seattle Mariners have cooled off some after their 13-2 start, going 5-12 since April 11. Even so, they’re another team with better playoff odds (15 percent as of Tuesday) than we’d expect from their offseason dealings — which included losing free agent slugger Nelson Cruz and trading ace pitcher James Paxton, closer Edwin Diaz and star second baseman Robinson Cano. Even through its recent slump, Seattle maintains MLB’s third-highest batting WAR courtesy of big years from Daniel Vogelbach (224 OPS+ !), Omar Narvaez (140) and Tim Beckham (139), to go with the usual mashing by Edwin Encarnacion (136), Domingo Santana (131) and Mitch Haniger (131). Starter Marco Gonzalez has also delivered an unexpectedly great season thus far, with a 150 ERA+ that has him leading the AL in pitching WAR. Seattle’s big home run rate (4.7 percent of all plate appearances) is out of line with its batted-ball metrics, and the team’s defense remains abysmal, so it’s no surprise that a regression has already begun to set in. But by virtue of their early record — still among the best in baseball — the Mariners will have to decide whether to try to end the franchise’s long-running playoff drought by making upgrades this season or to keep biding their time for a future postseason run.

Check out our latest MLB predictions.

CORRECTION (May 2, 2019, 11:40 a.m.): An earlier version of the table in this story listed the wrong division for three teams. The Tampa Bay Rays and Toronto Blue Jays play in the AL East, and the Philadelphia Phillies play in the NL East.