America’s favorite pastime has gone through some changes. The rules are still the same, but the way the game is managed is no longer what it used to be.

The change has been driven by analytics, which is information created by systematic analysis of data or statistics. Many Major League Baseball (MLB) franchises have analytic departments that determine who the team puts on the field, who manages the game, and what the best matchup is for each player based on their numbers. Sabermetrics is what the MLB primarily uses when referencing analytics and numbers.

The game has now changed in many ways, such as managers focusing more on lefty batter vs. lefty pitcher matchups. These lefty v. lefty matchups have always been looked at, but mostly later in games when managers would use their bullpens. This movement has stemmed from numbers saying that left handed batters do not fare well against southpaws on the mound.

Another big change has been with starting pitchers. Starters used to throw as many innings and pitches as they could if they were pitching well. Managers used to try and avoid using their bullpen, as the arms were not as reliable.

Now, teams are built to have strong bullpens. Starters only throw five innings, opposed to seven, as the managers like to try and prevent any big mistakes. The number of innings starters throw is based on pitch count, which managers rarely let go over 100 to try and prevent an injury.  The numbers throughout the league say that batters are more successful against a starter once they are seeing him for a third time, too.

Not only has pitching changed, but so has the way games are managed. Some differences are how teams build their lineups, shift their defenses and use their bullpen. Lineups are now built based on whose numbers fit best. For example, the second spot in the lineup tends to get the most RBI opportunities in a game. Teams will set up their lineup so their best hitter hits second, which is contrary to the belief that the best hitter should hit third.

Teams now look into where players hit the ball. This is mostly used against lefties, where teams will move players out of their routine positions to try and get specific players out. Almost all teams in baseball use the shift, and teams like the Astros will move all but one player to one side of the field against a hitter like Joey Gallo, who tends to pull the ball often.

Bullpen use has changed as well, as the format used to be the same for every team. Teams had a closer for the 9th inning, set-up man for the 8th inning, a few guys that were able to pitch the 6th or 7th innings, a long arm that could come into the game early in case the starter struggled, and left handed specialists.

Now, bullpens will be used in all sorts of ways. This season, teams have used their bullpens to actually start games, closers have been in potentially harder innings, and lefties have been used whenever the opposing team sends up a lefty.

Brian Kenny, a highly touted analyst for MLB Network and ESPN is one of the main guys who has helped bring analytics into baseball.

“It’s an advancement of knowledge in baseball,” Kenny said. “It helps teams win and it makes it easier to manage teams as they just follow the numbers.”

Stats have always been a part of the game and they help everyone judge a player’s season. They help set a baseline for what is above and below average and players have gotten paid based off of that. The issue that people have with analytics and judging the game completely off of the numbers is that it takes away all of the intangibles.

Arguments say that team chemistry, locker room presence, momentum and specific traits are taken out of the conversation when talking about analytics.

Baseball is a streaky game with players getting hot and cold. All players go through a stretch where anything they hit finds a way to elude a glove, and stretches where it’s the other way around and people make plays. Analytics looks past that and says that following the numbers will prevent that.

All in all, baseball is evolving and the evolution of America’s pastime is being fueled by analytics. The game is played much differently now than it was before and it will continue to change. The game will always evolve as teams find new ways to win and analytics are currently helping teams manage and find the best way to win games.