There has long been an adage in baseball that once we hit Memorial Day, teams have a pretty good idea of what they are. At that point, there are enough games in the books to make reasonable assessments of the results, so you can begin to plot out the rest of your season accordingly.
Because the adage is an old one, it's doubtful many chief decision-makers around the majors pay any heed to it, even if they might fall back on it in interviews. It's all about sample size, really, a statistical term that you hear so often these days. That's the main use of the idea, in fact. Though there is nothing inherently magical about Memorial Day as a benchmark in the baseball season, treating it as such helps keep journalists and fans alike from overreacting to an inadequate body of evidence. In theory, anyway.
Let's consider some diversions in performance among teams this season using the standings through Memorial Day compared to those through Wednesday of this week. We'll use expected win totals per 162 games (or Pythagorean records), which are based on run differential rather than actual win-loss records to iron out some luck factors, though the story is similar either way.
The old adage ain't exactly holding up this season. Only the New York Mets could have looked at their performance through Memorial Day and declared, "We are what we are!" And it would have been a horrible realization for that beleaguered fan base. There are a lot of stories in that table, but let's focus at the happy end, where the Washington Nationals, San Francisco Giants, Miami Marlins and Cleveland Indians have all improved their play by a rate of at least 25 wins per 162 games. Then let's set aside the Marlins, who are actually a pretty good story but are still nowhere near contention despite their two-month bounce-back.
As of Memorial Day, the Nationals and Indians were baseball's two most disappointing teams. Cleveland entered the season as the heavy favorite to repeat as AL Central champions for a fourth straight season but as of May 27, the Tribe were already 10 games behind the Minnesota Twins. The Nationals were expected to be part of a four-team superdivision in the NL East but found themselves 10 games under .500. Meanwhile, the Giants, entering a brand-spanking-new rebuild under new chief executive Farhan Zaidi, were also 10 games under break-even and had the second-worst run differential in the National League.
Since then, the Nats and Indians have moved into the top wild-card slots in their respective leagues, while the Giants are only a couple of games back for the second wild-card slot in the Senior Circuit. These teams' turnarounds have been extreme. Just to focus that point around Washington, only four teams have ever had a greater increase in winning percentage from the 50th game in a season to the 100th, according to ESPN Stats & Information. It's been incredible.
What has been the key? Well, as you'd expect, the story has been a little bit different for each team. So let's take them separately in search of some commonalities.

Washington Nationals
We start with Washington, which has recovered from its awful beginning by simply playing better. That's not exactly ESPN-level analysis, so allow me to elaborate.
The Nationals have risen from 17th in runs per game before June 1 to 10th since. That's not a stunning leap, but anytime you're hovering around the middle of a category and move into the upper third, you're surpassing the tipping point into a lot of wins. Washington projected to rank 12th in runs this season according to my preseason forecast and currently stands 13th. In many ways, that's the story of the 2019 Nationals: They ended up being what we thought they were, but the route they took to get there was plotted as if their GPS unit went completely haywire.
Unlike the Giants and Indians, the Nationals have gotten more offense with virtually no roster churn. Every position player who has logged a plate appearance this season remains on the 40-man roster. The Nats did pick up Gerardo Parra in early May after San Francisco had set him adrift, and Parra has been productive during his time in Washington. Mostly, though, the Nationals have improved just by doing better:
Nearly every Washington hitter who has a significant number of plate appearances the past two months has performed at a starkly better clip than he did earlier this season. Stars Anthony Rendon and Juan Soto have regressed, but they've remained excellent, and you can make the same statement to a lesser degree about Howie Kendrick.
As for the Washington rotation, that group has been excellent all season. The Nationals ranked seventh in rotation ERA before June 1 and have ranked second since, the latter a surprising result given Max Scherzer's recent absence. All in all, though, the Nationals' starters have performed up to expectation.
Early in the season, the story of Washington's pitching staff was the horrendous collective performance by Dave Martinez's bullpen. Through the end of May, Washington had an MLB-worst 7.06 bullpen ERA and had blown exactly half of its 22 save opportunities. On a seemingly nightly basis, the bullpen melted down in a fashion that threatened to define the Nats' season.
Since June 1, Washington's 4.07 bullpen ERA has ranked eighth in the majors and they've converted 16 of 24 save opportunities. It's still not the strongest group on the roster, but there is so much talent elsewhere that these numbers have been more than good enough for the Nationals to return to contender ranks.
There has been a bit of churn here. Veterans Dan Jennings and Trevor Rosenthal were both released, and veteran Jeremy Hellickson -- who made seven relief appearances -- is also off the 40-man roster and on the 60-day IL. Kyle Barraclough was demoted. All of these pitchers were penciled in for key roles before the season. Fernando Rodney and Jonny Venters were added and have done well.
However, some of the Nationals' relievers have simply picked up the pace. Key setup man Wander Suero's ERA has improved from 6.85 before June 1 to 3.13 since. Sean Doolittle has been solid all along, but he has gone from 3.52 to 1.80. Matt Grace has leaped from 7.23 to 3.77. Tony Sipp has gone from 5.73 to 1.13.
So for the Nationals, the approach has been to remain patient with their position group and rotation while swapping out the weak spots of the struggling bullpen. It's an approach that has saved a floundering season.

Cleveland Indians
While the Indians might have been preseason favorite to repeat in their division, they didn't exactly enter the season with a lot of positive buzz. With a quickly shrinking window of contention, Cleveland's passive offseason approach raised a lot of eyebrows. The roster looked top-heavy, and when stars such as Francisco Lindor, Corey Kluber, Carlos Carrasco and Mike Clevinger all ended up absent for long stretches -- and Jose Ramirez struggled badly out of the gate -- this lack of depth seemed certain to lead to an early teardown of this version of the Tribe.
Through Memorial Day, Cleveland was under .500, sported an appropriate run differential for that record, and ranked next-to-last in scoring in the American League. The pitching had been solid, if not elite as forecast, but the holes in the Indians' lineup -- that seemed apparent to the projection systems on Opening Day -- looked like gaping chasms.
In the Indians' case, the Chris Antonetti-led front office did not stand pat. No, Cleveland didn't make any of the splashy additions we wanted them to make last winter. Instead, they followed the path that teams with sound processes usually do: They looked to improve on the margins and hoped it would add up to a meaningful overall upgrade.
This is something teams have gotten way better at and I suspect this has to do with a talent pool that is larger than ever. True impact players are as precious as ever, but there are more capable players than at any time in the history of baseball. That's a subjective statement, but I think you'd be hard-pressed to prove me wrong. What this means is that if a controllable player, with little in terms of financial investment made in him, struggles, then you start trolling around for someone else who might be having a career season, or who has a skill set you think you can turn into something useful. The Tampa Bay Rays, Los Angeles Dodgers, Milwaukee Brewers and others have flourished with this approach in recent seasons.
The Indians had six hitters who received meaningful playing time during the early struggles who are either no longer on the 40-man roster or are no longer sucking up big league at-bats: Leonys Martin, Carlos Gonzalez, Hanley Ramirez, Brad Miller, Max Moroff and Eric Stamets.
That leaves us with the following table of the hitters Cleveland has leaned on the most during its surge:
The improvement has been universal, and you'll notice that none of the highest risers are star players. This is the bet that the Indians made in the offseason -- that they'd be able to develop solutions and depth from within. It's a bet they are winning at the moment. Since June 1, Cleveland is tied for fifth in runs in the AL, more than good enough to support what has been the stingiest run prevention during that span. The Indians have the best run differential in the American League since the beginning of June and closed within two games of the AL Central lead.

San Francisco Giants
San Francisco's story is similar to Cleveland's, albeit one that has sprung from a very different preseason narrative. Virtually no one expected the Giants to contend. Like Cleveland, the Giants did little in the offseason to add to their aging roster, at least from the standpoint of headline-making additions. Zaidi was plenty busy, though, churning the back half of his 40-man roster, a process that has been ongoing almost since the day he was hired.
We'll begin with the Giants' pitching staff. San Francisco entered the season with what looked like a strong bullpen group and the relievers have performed up to expectation. The Giants ranked seventh in bullpen ERA before June 1 and have ranked sixth since. For the season, San Francisco has converted 27 of 33 save chances.
This is precisely why, with the relievers joining stud postseason starter Madison Bumgarner, San Francisco seemed well-positioned to sell at the trade deadline. Every contender needs bullpen help -- all of them. From Will Smith to Sam Dyson to Tony Watson to Reyes Moronta, San Francisco looked like a one-stop-shopping locale for wannabe contenders.
To be sure, the season looked as if it were playing out according to plan for a long time. I mentioned the Giants' lackluster standing on Memorial Day. But their struggles persisted well beyond that. San Francisco was 10 games under .500 as late as July 1. That means they'd played break-even ball for a few weeks, but going from terrible to average is not exactly a formula for a World Series run.
Then the Giants simply stopped losing. They won 17 of 21 after June 30.
The starting pitching has been much better. The Giants were 25th in the majors with a 5.48 rotation ERA before June 1; they are seventh with a 4.04 ERA since. This has been the result of a combination of better performance (Bumgarner, Tyler Beede, Drew Pomeranz), consistent performance (Jeff Samardzija) and lineup changes (Shaun Anderson in, Dereck Rodriguez out). Mostly, the Giants have made it work with patience. Even Anderson's ERA (4.94) is pretty much a mirror of what Rodriguez was doing.
The real energy source for the Giants' stunning surge has been the offense. San Francisco has scored 1.5 more runs per game since June 1 than before it, jumping from 28th to 12th in ranking. Like Cleveland, part of the reason is roster churn. The long list of hitters who made appearances before June 1 who have barely been seen since, or are out of the organization altogether, includes Steven Duggar, Aramis Garcia, Zach Green, Mike Gerber, Yangervis Solarte, Mac Williamson, Erik Kratz, Connor Joe, Michael Reed and Aaron Altherr.
That leaves us with this familiar-looking table:
Zaidi has gotten a lot of mileage from what appeared to be fringy-looking additions such as Dickerson, Yastrzemski and Vogt, while some of his veterans have gotten hot. Of the three teams looked at here, this one looks to have the shakiest foundation. But the end result is what it is: The Giants have climbed to the right side of .500 and, by the standings, are in the thick of the playoff race.
You have to give the Giants credit. In Bruce Bochy's last season, with absolutely no weight of expectation upon them -- from the front office to the dugout to the playing field -- they've treated this season for what it is: an opportunity. When you look at how other "rebuilding" teams have slogged through their seasons (ahem ... Detroit), that's not nothing.
Extra innings
1. A postscript to the above: The Indians and Nationals are clear buyers at the deadline when looked at through the prism of playoff contention. Cleveland isn't likely to add payroll, similar to the winter, and if the Indians fall off, it'll raise another fresh round of howling. Washington, on the other hand, is positioned to make only targeted acquisitions to its roster, though the need for another high-octane reliever to take some burden off Doolittle in October seems essential.
As for the Giants, there has been a lot of debate about how much, if at all, their surge should affect Zaidi's deadline approach. To be sure, when you look at San Francisco's negative run differential and the number of regression candidates in its lineup, this hot stretch could turn cold at any moment. Others have pointed to the early-season Seattle Mariners as an example of a middling-or-worse roster overachieving for a couple of weeks. It's worth remembering.
However, if the Giants continue to play well up to the end of the month, there is no earthly way they can sell at the deadline. They've won from the wild-card slot before. It's Bochy's last season. Their fan base has been one of the most loyal and fervent in baseball for years, making the Giants a revenue behemoth. No matter how efficient it might be to take the long view, you simply can't do it to your fan base, or to your Hall of Fame manager.
Alas, the Giants could very well go into a tailspin over the next week and render this debate moot. For Bochy's sake, I kind of hope they don't.
2. One name to watch: Keon Broxton. It has been a rough year for Broxton, who has been moved from the Brewers to the Mets to the Baltimore Orioles since the end of last season. This week, Baltimore designated him for assignment. However, even if Broxton can't get it going at the plate, he offers a contender two key traits: a plus glove in center field and a threat on the basepaths. He can win games for you without hitting, though he has been a power threat through his career. The Philadelphia Phillies seem like a good fit.
3. This season for Houston Astros rookie Yordan Alvarez has been one for the annals. He made all the highlight reels this week for setting a new record for the first 30 games of a career with 35 RBIs, breaking the mark of Albert Pujols. Consider this: Alvarez's per-162 game pace as a big leaguer so far is .320/.397/.664 with 56 homers and 177 RBIs. He's 32 games into his career, so it's not fair to really project him out that far in this fashion. It does give you an idea of just how good he's been to date.
But that's not even the most stunning thing you can do with Alvarez's numbers. He has played at two levels for the Houston organization this season -- Triple-A and the majors. Together, he has driven 106 runs in 88 games! That's a pace of 195 RBIs per 162 games. Hack Wilson, look out.