The 2010s were a decade of huge revenue growth for Major League Baseball, but it was also marked by significant changes in how the game was played and by storm clouds gathering on the horizon when the decade ended.
The 2010s was the decade during which analytics took over in Major League Baseball. All teams created departments dedicated to the advanced analysis not only of statistics but of all sorts of newly available data gathered through systems such as Statcast, which provided extremely detailed information on all movements on the field, be they of players or of the ball. This data was used to change tactics, for example the boom in usage of defensive shifts or the growing popularity of bullpen games, as well as the approach by batters who were all about getting a better launch angle and higher exit velocity on batted balls, or pitchers whose mantra was velocity and spin rates. Not everyone was comfortable with this evolution, as it meant a boom in the so-called Three True Outcomes (strikeouts, walks and homers) and a decline in batted balls, baserunning and fielding plays. Combined with a deliberate approach by many teams of taking pitches in order to increase the opposing starter's pitch count, and the multiplication of pitching changes, this made for a slow-paced and sometimes boring game. Some were decrying the end of baseball as we knew it and its inevitable decay as a spectator sport, but no one was really sure how to address pace of play issues, as the steps taken, such as limiting mound visits and making the intentional walk automatic, seemed to have little or no effect. In fact, allowing the widespread use of instant replay had as much negative impact on game duration as any gains from these measures. Thus, as the decade ended, much more radical measures were being contemplated, including rules to change the composition of rosters in an attempt to curb the proliferation of nameless relief pitchers shuttling between the back of the bullpen and AAA; limits on pitching changes; limits on defensive shifts; the possible introduction of "robot umpires" to call balls and strikes; tinkering with some of the distances on the field, etc.
When the decade ended, many observers noted that it had been the first since the 1910s in which the New York Yankees had not appeared in a World Series. This was a sign of increased parity on the field, as the San Francisco Giants won their first three titles since moving to the West Coast at the end of the 1950s, the Chicago Cubs ended a historic drought of over a century by winning the World Series in 2016, both the Houston Astros and Washington Nationals won their first-ever championships, and teams like the Kansas City Royals, Toronto Blue Jays and Pittsburgh Pirates ended long postseason droughts while the Texas Rangers reached the World Series for the first time. The 2016 World Series, which featured an epic showdown between the Cubs and Cleveland Indians, the two teams with the longest championship droughts at the time, was the highlight of the decade, but there were a number of other exciting postseason series throughout the decade.
The biggest stars in the majors included Mike Trout, Adrian Beltre, Miguel Cabrera, Bryce Harper, José Altuve, Clayton Kershaw, Max Scherzer, Justin Verlander and Stephen Strasburg. Among the outstanding individual accomplishments was Cabrera achieving the first Triple Crown in over four decades in 2012. Mariano Rivera set the all-time record for saves with 645 when he retired in 2013, and then became the first player to be elected unanimously to the Hall of Fame in 2019. Trout won three MVP Awards in addition to being the Rookie of the Year and Pete Alonso ended the decade by setting a new record for most homers by a rookie; in previous years, both Aaron Judge and Cody Bellinger had also put up huge home run seasons as rookies. In terms of career milestones, five players joined the 3000 hit club - Derek Jeter, Beltre, Albert Pujols, Alex Rodriguez and Ichiro Suzuki - but only two made it to 500 home runs - Pujols and David Ortiz. On the pitching side, no one made it into the hallowed circle of 300-game winners, and we had to wait until the final year of the decade, 2019, to see CC Sabathia and Verlander record their 3000th strikeout.
The most significant scandal of the decade was the one connected with Biogenesis Laboratories, a Miami, FL-based enterprise whose main side-business was procuring PEDs to various professional athletes. After the story was revealed by the Miami New Times in early 2013, MLB had no choice but to investigate and take some sweeping penalties for athletes caught in the net. The most prominent figures were Rodriguez and Ryan Braun, although there were numerous others, including minor leaguers. Rodriguez was suspended for a full season in what marked the beginning of the end for him, and others also got lengthy penalties, although some were able to return for the postseason after serving out their suspension. This did not go down well with fans, and the Joint Drug Prevention and Treatment Program was later amended to ensure that anyone testing positive for a PED during the season would automatically be ineligible for that year's postseason games. The other scandals revolved around cases of domestic violence. Baseball finally began to take the issue seriously, and a number of athletes were suspended for long stretches as a result of investigations into allegations of domestic violence, including Aroldis Chapman, Addison Russell and Roberto Osuna. At the very end of the decade, in the fall of 2019, it was revealed that MLB was investigating the Houston Astros for having set up an illegal system to steal their opponents' signs during their 2017 championship season, an investigation later extended to the 2018 Red Sox. As the investigation corroborated the allegations, harsh punishments were handed, including a fine, the loss of draft picks, and the suspension of executives who allowed the scheme to be implemented.
The minor leagues were relatively stable during the decade, with decent attendance and limited franchise movement, and no leagues in organized baseball folding or being significantly re-shaped. The trend of moving from small towns to more suburban locations with a family-oriented product continued. There was a major trend of teams getting new and very distinctive nicknames, largely for marketing purposes. Thus were born the Sod Poodles, Baby Cakes, Jumbo Shrimp and Rumble Ponies among a slew of improbable team names, although there was a bit of a backlash at the end of the decade, with the appearance of AAA teams named after the parent major league franchise, such as the Oklahoma City Dodgers and Syracuse Mets.
But as the decade ended, a huge thunderstorm was about to hit the minor leagues, as following the 2019 season, MLB proposed cutting 41 teams and eliminating a couple of classifications after the 2020 season, in order to cut operating costs and increase salaries paid to minor leaguers (MLB was under pressure because of lawsuits filed by players highlighting how little they were paid for what amounted to a full-time job). Various independent leagues continued to exist in parallel, with the most prominent ones (the Frontier League, the Atlantic League and the American Association) having found a measure of stability, but others like the Pecos League or Can-Am Association just staying in business from year-to-year with little indication of longer term viability.
In spite of gloomy talk about baseball's drop in popularity, revenues were at an all-time high, thanks to solid attendance figures, although there was a small dip at the end of the decade. Also contributing to the general prosperity were record-breaking television contracts, particularly by regional sports cable networks; significant revenues generated through the internet including through fantasy baseball; and solid merchandising income. What was missing was the past dominance of baseball on the cultural landscape. Even with professional football taking a hit during the decade after years of uninterrupted growth, baseball did not step into the breach in terms of visibility of its top stars and television ratings for national contests, including the World Series, continued to trend downwards. There was a sense that baseball was at odds with demographic trends, with an audience skewing older and whiter than the general population, and had trouble holding the attention of youth who were said to lack the attention span to sit through three-hour games. But given this audience was also richer and had more disposable income than the average, for the time being there was a sense that the good times were still rolling.
The demographic problem was also visible in youth participation, as baseball was slowly moving into becoming an elite sport in the United States, with cheap and near universal participation in Little League Baseball giving way to regional and travel teams demanding a huge financial and time investment by parents, similar to what was happening in hockey or other sports played entirely outside inner cities or minority communities. Thus professional baseball players were mainly middle class white American kids from the suburbs, and Latinos from much less comfortable backgrounds originating in places like Venezuela or the Dominican Republic. This was a far cry from the days when immigrants from the inner cities and small town kids made up the bulk of the professional baseball demographic. But there were some positive trends also, as female participation in baseball grew significantly during the decade, and the Urban Youth Academy model sponsored by MLB was a big success.
There was franchise stability during the decade, although the Florida Marlins changed names to become the "Miami Marlins" when they moved in to a new ballpark in 2012 and the Astros switched from the National League to the American League in 2013, giving both leagues 15 teams spread over three divisions of five teams each. The Los Angeles Angels quietly dropped the "of Anaheim" appendix from their name after the expiration of the ten-year period during which they were obligated to mention their true home city, but there was no franchise relocation or expansion. However, after years when expansion was completely off the table, talks about a new expansion that would bring the major leagues to 32 teams grew in frequency as the decade advanced, with Montréal, QC, Mexico City and Portland, OR among the cities most often mentioned as future major league sites. But before this could go ahead, MLB had to fix the vexing problem of outdated ballparks still used by the Oakland Athletics and Tampa Bay Rays; there was light on the horizon for the A's as the decade ended, but still no viable plan to replace Tropicana Field or to move the Rays, who were seemingly incapable of drawing fans in spite of putting a competitive team on the field. There was little ballpark construction during the decade, apart from the aforementioned Marlins Park and for Sun Trust Park in Atlanta, GA, which was nice but not trend-setting. However, plans had been launched to replace ballparks in Texas and Arizona in spite of the fact the existing structures were not particularly old or problematic.
One worrying trend was that some teams had discovered the virtues of "tanking": deliberately losing a huge number of games for a few seasons in order to assemble a strong core of young players through the amateur draft and trades. It had worked for the Astros, but in other places, it was just perceived as dumping on the fans who still had to pay good money to watch an inferior product, while the owners were raking in money from shared sources of revenue and the luxury tax. Also, as a result of analytics, player movement increased, as teams were reluctant to invest in veterans who gave teams a strong identity but were costlier than unproven players who could produce almost as much for much less, according to predictive metrics. It was also a result of many teams having been burned by prohibitively expensive long-term contracts offered to players about to start their decline phase, and still around years later when they were no longer productive (Chris Davis, Cabrera and Albert Pujols were the poster children for this) or who had been simply over-valued (e.g. Jordan Zimmermann). This new reality created a depressed market for certain free agents, most visibly after the 2017 and 2018 seasons when there were dozens of unsigned well-known players as spring training rolled around. And then just when it was trendy to proclaim that free agency was unremittingly broken, there was a flood of money being thrown at free agents after the 2019 season.
In the Americas, the Caribbean Series expanded from its historic four-team model, with the addition of Cuba and later Panama to become a six-team event, with plans to expand to Nicaragua and Colombia as well. It marked part of Cuba's increased connections with the rest of the world, which also played out in Cuban stars being given permission to play without having to defect in Nippon Pro Baseball, the Mexican League, Canadian-American Association and Italian Serie A1 among other leagues. Several of Cuba's biggest names, like Alfredo Despaigne, Yurisbel Gracial and Livan Moinelo, starred in Japan. Part of the move was to deter the increased flow of Cuban defectors, who included Aroldis Chapman, Jose Abreu and Yoennis Cespedes. The combination of players being permitted to play overseas and defectors riddled the Cuban Serie Nacional, whose quality kept falling. The Cuban national team was hammered by the defections as it went from still being a top world power in the 2000s to a mid-level power in the 2010s. The other big change in the Americas was increased violence and political chaos in Venezuela causing the closure of the Venezuelan Summer League while some major league players died or were kidnapped as part of the violence.
In Asia and Australia, the Asia Series came to a close after 2013 while Asia's top leagues were relatively stable. The Korea Baseball Organization expanded from 8 teams to 10, while the Chinese Professional Baseball League had its decade with the fewest scandals yet. The China Baseball League was shut down for a couple of years but was revived. The Australian Baseball League was revived after a decade's hiatus and was successful, expanding to New Zealand despite the loss of MLB funding.
In Europe and Africa, the game continued to develop. The decade saw the first major leaguers from South Africa (Gift Ngoepe), Lithuania (Dovydas Neverauskas), the first major leaguer raised in Germany (Donald Lutz), the first major leaguer born and raised in Italy (Alex Liddi) and the first major leaguer born and raised in Germany (Max Kepler), with Kepler becoming a star by decade's end.
International tournaments changed drastically. Baseball was not played in the Olympics for the first time since the 1970s, although it was slated to return temporarily in 2020, while the Intercontinental Cup ended in 2010 and the Baseball World Cup (with origins dating to the 1930s) ended in 2011. The World Baseball Classic continued to feature baseball's biggest names, with tournaments held in 2013 and 2017, while the Premier 12 featured the top players from Japanese, South Korean, Cuban and Taiwanese leagues while teams from elsewhere in the Americas were limited by the unavailability of players on 40-man rosters; Team USA relied on top prospects and a few journeyman ex-major leaguers, for instance. Women's tournaments increased, with the Women's Baseball Asian Cup and European Women's Championship joining the Women's Baseball World Cup, which had outlasted the men's Baseball World Cup.
- Douglas Jordan: "Home Runs and Strikeouts: Another Look", Baseball Research Journal, SABR, Vol. 47, Nr. 2 (Fall 2018), pp. 28-31.
- Will Leitch: "These are the 10 best players of the decade", mlb.com, November 26, 2019. 
- Will Leitch: "10 stories this decade that shocked us", mlb.com, December 5, 2019. 
- Will Leitch: "10 random legends of the 2010s", mlb.com, December 26, 2019. 
- Ben Lindbergh and Travis Sawchik: The MVP Machine: How Baseball's New Nonconformists Are Using Data to Build Better Players, Basic Books, New York, NY, 2019. ISBN 978-1541698949
- Rob Neyer: Power Ball: Anatomy of a Modern Baseball Game, HarperCollins Publishers, New York NY, 2018. ISBN 978-0-0628-5361-5
- Bob Nightengale: "Decade of sports: Cubs winning 2016 World Series was best moment of the 2010s", USA Today, December 20, 2019. 
- Jesse Yomtov: "Best of the decade: MLB dream team, position-by-position", USA Today, December 11, 2019. 
|Years||American League||National League||Postseason||Japan|
|2010||2010 AL||2010 NL||2010 WS||2010 in Japan|
|2011||2011 AL||2011 NL||2011 WS||2011 in Japan|
|2012||2012 AL||2012 NL||2012 WS||2012 in Japan|
|2013||2013 AL||2013 NL||2013 WS||2013 in Japan|
|2014||2014 AL||2014 NL||2014 WS||2014 in Japan|
|2015||2015 AL||2015 NL||2015 WS||2015 in Japan|
|2016||2016 AL||2016 NL||2016 WS||2016 in Japan|
|2017||2017 AL||2017 NL||2017 WS||2017 in Japan|
|2018||2018 AL||2018 NL||2018 WS||2018 in Japan|
|2019||2019 AL||2019 NL||2019 WS||2019 in Japan|