From an American perspective, two of the most memorable things about the year 1919 were baseball events: Babe Ruth was traded from the Red Sox to the Yankees, and the White Sox threw the World Series. (Also: the Anarchist bombings, the Great Molasses Flood and the Treaty of Versailles.) What's interesting about those two events is that neither would have been known to the average baseball fan at the close of 1919: Ruth's deal wasn't made public until the first week of 1920, and the White Sox weren't investigated until September 1920.

So, as always, we very humbly acknowledge that the search we're about to embark upon -- to determine what, from the 2019 baseball season, will be well known to the average baseball fan many decades from now -- is beginning at least 20 years too early. To reinforce that point: The most lasting memory from the 2017 season is likely to be the World Series champion Astros banging trash cans in a high-tech/low-tech sign-stealing scam. We learned about that just this fall.

We once again use as our road map The Definitive Guide To What Gets Remembered, our survey of the sport's most resilient stories, from Murderers' Row to Mazeroski's walk-off to McCray running through a wall. That guide gives us the seven categories of not-forgotten things of the past to organize our search.

Category 1. Incredible achievement, usually captured by a single number or concept

The last time home runs spiked, in the 1990s and early 2000s, there were a bunch of new individual home run records. But the nature of this year's power surge -- a livelier ball that seems to benefit almost every player equally, rather than a few players disproportionately -- kept any individuals from demolishing previous offensive standards. And the emphasis on home runs ruled out any other extreme performances -- nobody is going to steal 100 bases, or bat .400, or goodness gracious set many pitching records, when home runs come as cheaply as they did this year.

So while there were great seasons -- Christian Yelich was the 29th player in the past century to win the slash-stat triple crown, Mike Trout set career bests in power stats, Gerrit Cole broke the record for strikeouts per nine innings -- there wasn't a single number that jumps and stays out. The best candidates:

• Pete Alonso's rookie record 53 homers. It's a bit less exciting coming just two years after Aaron Judge broke the previous record (in another rabbit-ball season). It hurts, too, that Alonso didn't stick out, as a visual and a phenomenon, like Judge did. Judge was, by the end of that season, the most popular player in baseball, and Alonso is not. It is, on the other hand, a legitimate record (rather than mere fun fact), and Alonso's emergence as a juiced-ball denier might extend his baseball Q score, as future generations continue to debate what exactly was going on in this era.

• Stephen Strasburg's postseason performance: a record-tying five postseason wins, 47 strikeouts against only four walks. It suffers in comparison to Madison Bumgarner's superior-by-any-measure postseason in 2014, and in comparison to Bumgarner's larger body of postseason work, and because Strasburg didn't get to pitch that all-important (for historical purposes) seventh game. On the other hand, Strasburg is a more famous pitcher than Bumgarner, and his whole career is more likely to be remembered generations from now.

• Mariano Rivera being unanimously elected to the Hall of Fame. If he is somehow still the only unanimous inductee many decades hence, this is probably the correct answer for the whole article. But he won't be. The shift in voting norms -- and Rivera breaking the seal -- probably heralds a bunch of followers: Who'll vote against Ichiro now that we've disposed of the tradition of withholding votes on the first ballot? Who'll vote against Kershaw? Nobody could conceivably vote against Trout.

• Trout's contract extension ($426 million-ish) or Gerrit Cole's free-agent contract ($324 million). Each is a record -- Trout's for biggest contract and highest average annual salary, Cole's for a pitcher -- and each will probably remain the record for a half-decade or more. And now that fans process so much of the game through the GM's lens, many of us know player salaries more precisely than we know their stats. On the other hand, though, salaries almost always go up, and Trout and Cole will both be dwarfed within decades and devalued by our collective inability to adjust for inflation. The only modern contract that seems broadly remembered decades later is Alex Rodriguez's $252 million deal in Texas. Otherwise, we have to go back to the era when fans could still be shocked by players' (relatively modest) salaries -- Ruth making more than the president, Joe DiMaggio cracking $100K -- to find numbers that were still repeated a generation later.

Category 1(b). Incredible team (often captured by a nickname)

The Astros were, by talent, an all-time great team, with the highest third-order winning percentage since at least 1950, which is as far back as Baseball Prospectus tracks the stat. But the Astros didn't win the World Series, and third-order winning percentage is invisible to the average fan (and likely to be, along with all advanced stats, redesigned or replaced by more advanced stats in decades to come). If we're just thinking of the 2019 Astros as a group that played together in 2019, this is not a season on its own that will survive history.

If we think of the 2019 Astros as part of the Astros-in-the-2010s story, though, this was another memorable season. It was the year they became, clearly and nearly universally, the villains. Their trash-can-banging scam from 2017 was exposed, and turns out to have been so obvious that clips of it happening (THUMP! THUMP!) will air on baseball history segments for years. It was the year their assistant GM celebrated the pennant by taunting women reporters about the team's closer, who was arrested and charged with assaulting a woman in May 2018. That scandal might fade from memory, but it might also survive as a sign of a culture in need of correction, the same way Al Campanis' racist comments about black managers are still remembered three decades later.

Alongside all that, they really were an incredibly talented team -- Verlander and Cole alone! -- and their story arc seemed to reach completion: peak talent, peak villainy. This is the team everybody copied in the 2010s, and it felt at times like a team whose influence and mindset we needed to resist. There is absolutely no doubt there will be great books written about the Astros from 2011 through 2019, and even if 2019 was not the season they'll be most remembered for, it's a huge part of why they'll be remembered.

Category 1(c). Incredible single play or sequence of plays, often aided by iconic photo or video images

The home run that Howie Kendrick hit in the seventh game of the World Series -- turning a one-run deficit into a one-run lead, ultimately winning the title for Washington -- was the 10th biggest hit in baseball history, according to The Baseball Gauge's championship win probability added. But that's not enough to guarantee immortality. The biggest hit ever -- a Hal Smith homer -- is, most likely, new to you. Can you remember a Hal Smith homer? Have you ever heard of Hal Smith? (His was a home run that came an inning before Bill Mazeroski's, in Game 7 of the 1960 World Series. Mazeroski's walk-off was displaced from the No. 10 spot, on the cWPA leaderboard, by Kendrick.) Of the nine hits ahead of Kendrick's, I'd estimate only three are broadly "famous" in 2019 -- and those happen to be the three most recent ones.

Kendrick's other hope is his homer will go down as the biggest foul-pole homer ever. Nothing tells baseball's "game of inches" story quite like an entire season coming down to a ball hitting the foul pole. But (A) Kendrick hit the screen that extends out from the fair side of the pole, rather than the narrow cylinder itself, so it wasn't quite like kicking up chalk, and (B) Carlton Fisk already hit the foul pole, in the 1975 World Series. His homer didn't have the same effect on championship win probability, but Fisk's arm-waving produced a far more iconic game-of-inches visual. Fisk's foul pole was renamed after that homer -- the Fisk Foul Pole -- while Kendrick's, in Houston, will very much not be.

Category 2. The moment the timeline begins/the moment modern baseball begins

Earlier this year, I imagined the unlikely but plausible future in which the Home Run Derby splits off into its own sport and surpasses baseball in popularity. The catalyzing event for the rise of the Derby would be the $1 million prize that was added this year, which gives the Derby stakes it never had before -- particularly for young, salary-restricted players. And then, the players gave us one of the most entertaining Derbies ever -- Vlad Guerrero Jr. setting an all-time dinger record, Alonso effortlessly dominating the finals -- so it's obligatory to include it here.

It's unlikely the spread of the infield shift will be traced back to any single year, and if it is it'll probably be one of the years early in this decade, when a small number of teams started making it common. But as Ben Lindbergh first noted, two teams this year -- the Dodgers and Astros -- actually shifted on more than half of all pitches. In other words, for those two teams it was the traditional defensive alignment that now represents a "shift" -- the new alignment is now the default. Leaguewide that isn't true yet, but it still feels like a significant moment.

Category 3. Bloopers and/or extraordinary failures

It's a bit like a blooper: Yasiel Puig angrily fighting (and getting suspended for fighting) the Pittsburgh Pirates moments after he'd been traded to Cleveland, but before he knew it.

The clip's legacy will suffer a bit because Puig didn't do much more than jaw in it. Amir Garrett produced the punches in the brawl -- Puig made the punches in an earlier 2019 brawl against Pittsburgh, one that inspired a memey T-shirt he later wore -- but nevertheless, it's a story that'll be told and retold. And it succinctly tells a story of its own, about the arbitrary but inexorable power of a uniform. Puig hated the Pirates because he was a Red. He fought them because his team was fighting them. And the delightful irony of what we were watching was in him not knowing what we knew, which was that in about 10 minutes he would have no strong emotions against the Pirates (or in favor of the Reds) again. Indeed, we all kind of know that if Puig had been traded to the Pirates that day, and found out about it in the middle of the brawl, he probably would have switched sides right then and there and started yelling at anybody with a "C" on their cap. Perhaps nothing holds sports together like team identity, and the underlying arbitrariness of it all is the comedy that sneaks out in a moment like this one.

Chris Davis' hitless streak concluded this year -- 54 at-bats -- but unless MLB takes major steps to thwart strikeouts, I'd be shocked if that's still the record six decades from now.

Category 4. Pathos

Decades are often remembered for their drug trends, drug panics and drug crises, and in a larger, nationwide sense the 2010s will be remembered for the opioid epidemic. Tyler Skaggs -- an affluent Santa Monican in seemingly great physical condition -- is not the decade's emblematic opioid victim, but deaths like his scale the crisis for people who weren't already intimately affected by it. We still don't know whether opioid abuse is common in professional baseball -- there are some troubling hints -- so we don't yet know whether Skaggs' death will be a watershed moment. We can say, though, that the no-hitter his teammates threw when his spot in the rotation came up will be remembered as the most emotional combined no-hitter in history.

Category 5. Disruption of baseball's equilibrium

Two years ago, when considering whether 2017 would be remembered as the year of the juiced ball, we wrote this:

But whether we remember 2017 as the juiced-ball year depends on whether things go back to normal in 2018. If they don't, then 2015 -- as the start of the home run timeline -- will probably be remembered as the change year, and some future season in which even more home runs get hit will be remembered as the peak Year Of The Dinger. However, if the seams rise slightly and home runs dip by 20 percent next season, 2017 will be remembered as the year it reached absurdity, and decades of future fun facts will end with "... since 2017."

As it turned out, homers dipped by almost 10 percent in 2018 -- but then came back and more so in 2019, and it's now pretty much a lock that 2019 will be mostly remembered as The Juiced Ball Season until it gets surpassed. Nobody hit 74 homers, but almost any collective record that could be set was set: The year produced the top four homer-hitting teams ever, with the Twins blasting past the old record by 40. Half of the league's teams set franchise records for homers. Half of the league's pitching staffs did the same for homers allowed. The league set records for home runs at every position except first base (second all time) and pitcher. There were 34 games with at least six homers this year -- the previous record was 18. There were more 20-homer hitters than any season in history, and more 30-homer hitters, and more players with three-homer games, and -- in Philadelphia on June 10 -- the most homers ever hit (13) in a single game. Unless the home run spike goes up further, you will hear the words "the most since 2019" in broadcast fun facts until the end of time.

But it's not just that. This was the first year the fans all knew what was going on in real time, and in more detail than MLB seemed to know. Broadcasts were talking about the work of Meredith Wills -- who studied the minute physical characteristics of baseballs past and present -- and Rob Arthur, whose clever method of using pitch-tracking data to measure drag can detect changes just a handful of games into a season.

Because of that, the most significant thing that happened this year might be that fans and writers realized the extent to which the ball is, as Zack Kram wrote this month, "an unreliable narrator." Balls vary from batch to batch, and from ball to ball within batches, such that two fly balls hit precisely the same might land 5, 15, or even 30 feet apart. We realized we were living through the home run boom in a sort of quantum uncertainty. It was the first postseason, I think, when every home run or deep fly out was treated to a round of "juiced ball" or "dead ball" tweets. It was the first offseason in which transaction analysis ran into the wall of not knowing how next season's ball will fly. And it was the first time many of us wondered about the past: How much of baseball's history would have changed if the umpire had pulled a different ball out of his pocket? When we've been joking about "the baseball gods," have we been talking about drag variations the whole time?

Assuming this is beyond the power of Major League Baseball to clarify completely, we have decades and decades of pondering ahead of us. It's plausible we'll be talking about this openly, as text rather than subtext, a generation from now: After a home run one-row deep, the broadcaster will note the pitch location, will note how close the outfielder came to catching it, and will recite a boilerplate caveat: "With a different ball, perhaps ... "

Category 6. When the larger world intersects with baseball, or vice versa

Major League Baseball going to war with minor league baseball is a potentially huge story, and presidential candidate Bernie Sanders jumping into it provides the intersection, but the shuttering of teams next season is probably more of a 2020 story that will be remembered decades hence. Indeed, that is probably the 2020 story. Check back a year from now to see.

A sleeper in this category is the Nationals' use of "Baby Shark," which seems now like a passing memory of a passing fad. But imagine that "Baby Shark" isn't a one-time fad, but in fact has an every-10-years revival for each new generation of preschoolers: Remixes and covers, a movie franchise built around it, a Christmas version that can be synced to residential light displays, a sugar cereal, an amusement park ride, a celebrity naming their child after it, 1,200 choreographed dancers at an Olympics opening ceremony, toddler shoes that play it when they're walked in, etc. Imagine that in 100 years, "Baby Shark" is the most famous song from this decade. Quite possibly, in that scenario, we'll know everything about it, including that during the year it broke out as such a huge worldwide smash, the Nationals used it as their spirit jingle. It'll be part of the "Baby Shark" legend that the song good-luck-charmed a team to a championship.

Category 7. By being weird, by being almost literally unbelievable or inexplicable

Every World Series game being won by the road team is a solid weird fun fact, and those tend to get cited for decades whenever another team approaches them. However, this one was so weird, so statistically unlikely, that very few series will even make it to Game 4 without a home win. Which means this fun fact won't have cause to be cited all that often. I don't think it's strong enough as a fun fact alone.

But the Nationals as a champion were almost literally unbelievable and/or inexplicable, too. There was the 19-31 start, which even generations from now will quite likely still be the worst start by an eventual champion. Then there was the postseason run: Down in the wild-card game, down in the NLCS, down in the World Series, comebacks in each. And there is the strength of postseason competition: By wins, or by more advanced measures, the Braves/Dodgers/Astros combined to be the most talented vanquished opponents in the division era, and that's without even considering the Nats' extra challenge of winning the wild-card game. That this team had quite possibly four Hall of Famers -- including Max Scherzer, who gutted out a Game 7 victory with sub-Scherzer stuff after a Game 5 scratch -- will add to their legacy. They were all-time giant slayers.

All of these will be remembered by some segment of baseball fans. Nothing is ever truly forgotten anymore, and baseball fans constantly rediscover the charms of the sport's past. But if we're talking about broad and popular knowledge of 2019 baseball, I'd guess the top contenders go:

1. Juiced ball.

2. Astros' peak talent/peak villainy season.

3. Pete Alonso's 53 homers as a rookie.

Thanks to Craig Goldstein, Zachary Levine, Meg Rowley and Matt Trueblood for consultation.