How Home Runs and Batting Averages Have Changed Over the Last 30 Years

Remember back when the best hitters in the league were actually hitting above .300?

These days, you’re gonna hear baseball purists utter phrases like this as we watch the game of baseball transform into the “all-or-nothing” era.

It is undeniable that there are more home runs in baseball today and lower batting averages than years past. We’ll look at numbers soon which clearly show this.

Our goal today is to answer the questions that baseball fans have today? When did batting averages start declining? What is the current league batting average and how does it compare to league averages of years past? How many more home runs are there now? Has the criteria for a “good season” changed?

1994 is as far back as this research is taking us. There’s nothing special about this year statistically, but it marks the beginning of the steroid era and goes back far enough into time to allow us to see power numbers rise, then fall, then rise again.

Last month we explored how pitching has changed – namely how managers opt to use their rotations and how pitchers are throwing harder across the board.

Today is the hitters’ turn! Let’s go!

The Different Eras of Baseball History

If you know a little something about baseball history you know that several significant events and rule changes throughout the 20th century have split baseball statistics into different eras which each have their own nuances.

Dead-Ball Era

Hitters in the 1900s decade were in the dead ball era. The league lacked the modern machinery to tightly stitch baseballs and stadium lights were either nonexistent or a shell of what they are today. The result was poor hitting conditions and a ball that did not go as far. Ty Cobb won the home run crown in 1909 with 9 home runs.

WWII Era

The development of a new baseball broke the game out of the dead ball era and things remained relatively stable statistics-wise through the 20s and 30s until World War II caused a major shake up.

The MLB elected to continue playing through the war but many of its players were serving overseas. The minor leagues were hit especially hard.

In addition to personnel changes, the composition of the ball also changed during the World War II era due to materials being used in the war effort instead of baseball making.

Age of the Pitcher

Following World War II the game remained relatively the same from the mid 40s into the late 60s.

Throughout the 60s there was a strong trend emerging in the MLB – pitchers were becoming dominant and hitting stats were suffering.

Some baseball purists may have liked this defensive style of baseball but most fans called the lack of offense a problem. This “problem” reached its peak in 1968, which is dubbed The Year of the Pitcher.

Bob Gibson was the league’s best pitcher that year – leading the St. Louis Cardinals to the World Series (where they lost to my Tigers). In ’68 Gibson had a record of 22-9 with a sparkling ERA of 1.12 and a WHIP of 0.85. Gibby recorded 268 strikeouts in just over 300 innings – very good for facing an era of hitters which prided themselves in not striking out.

Gibson was not the only pitcher dominating that year – far from it. The league ERA in ’68 was 2.98 – the lowest since 1918.

If you think batting averages are low now, this fact may surprise you. Carl Yastrzemski won the 1968 American League batting title with an average of 301. Yes… 301. This is the lowest batting average to ever lead a league.

Lowering the Mound

League officials decided it was time to level the playing field, and the league lowered their mounds from 15 inches to 10 inches – the height that is still in use today. Forcing the pitchers to throw off a shorter mound took away a little bit of their edge and offense began to increase.

By the way, if you didn’t at least chuckle at my “level the playing field” pun … just leave right now. That was gold!

The Designated Hitter Enters the American League

The MLB decided that lowering the mound wasn’t enough. League officials wanted to make another rule change to infuse even more offense into the game – the designated hitter.

Prior to the 1976 season, pitchers had to bat for themselves in every single game – both leagues. In 1976, the American League gave teams the designated hitter option – allowing them to put a hitter in the lineup in place of any defender (MLB teams exclusively choose the pitcher as the defender to not bat).

Getting to replace your weakest hitting player with an athlete whose sole responsibility is hitting the baseball was another major source of inflation for offensive stats.

To this day, the National League has yet to incorporate the designated hitter (although it’s very likely they will within the next season or two). AL teams consistently score about 1 extra run per game because of the DH. In the case of an interleague play, the teams play by the host team’s rules.

The Ugly Steroid Era

As you would assume, offensive stats increased beginning in 1976. The game remained relatively the same until the 90s when steroid use became rampant.

Famous sluggers like Barry Bonds, Mark McGwire, and Sammy Sosa rose to fame during this era. They were beloved at the time until we later found out that they were cheating.

Easily the most controversial era in baseball, power stats exploded in the 90s and early 2000s before anyone got wise to the performance-enhancing drug use behind the explosion.

It was pretty obvious when the steroid usage stopped in the MLB as offensive stats returned to pre-steroid levels.

The Launch Angle Era

The game then remained the same through the 2000s and the early 2010s until offensive numbers began exploding late in the 2010s and into the 2020s.

2019 saw more home runs than any other season in MLB history. 2nd place is 2017, with 2016 the 4th-most, and 2018 5th. With 4 of the top-5 home run seasons in history happening within the past 5 years, long balls are undeniably trending up right now.

Many players and fans alike swore that the MLB was juicing their baseballs in an attempt to showcase more home runs. This may be so, but the approach to hitting has also changed and this is where looking at league batting averages comes into play.

The league batting average remained pretty steady through the late 70s, 80s, and even through a lot of the steroid drama in the 90s and early 2000s. The great steroid era home run hitters like Barry Bonds were mashing baseballs over the fence at an unprecedented pace but were still posting very high batting averages.

In the 11-season stretch from 1994-2004, Barry Bonds posted a batting average of .315. Sammy Sosa hit .287 during those same seasons while Mark McGwire also hit .287 from 1994 until his retirement in 2000.

All of the sudden, batting averages began to plummet as we approached the end of the 2000s decade. The graph shows a sharp decline which began around 2007 or 2008.

Understanding what caused this drop will give us lots of useful information whether you are betting on the games, playing fantasy baseball, or just want a deeper understanding of the game when watching it for pure enjoyment.

What is Launch Angle Hitting?

The launch angle theory of hitting became very popular right around the time batting averages began declining. The theory is as follows: a perfectly squared up baseball results in a line drive. Line drives have the highest chance of resulting in a hit of the three hit types (ground ball, line drive, flyball) but rarely result in home runs.

For the longest time baseball players were trying to hit line drives. Line drives rarely result in home runs and it doesn’t take a baseball expert to realize that fly balls are the most common hit type resulting in a home run.

There’s an old expression in baseball that a home run was a mistake by the hitter. If a hitter is trying to hit a line drive but he instead gets under the ball a little bit and lifts a fly ball that goes over the fence, it’s a good result but he actually mis-hit the ball a little bit.

Then somebody came up with a revolutionary idea. What if hitters tried to hit fly balls as their primary goal instead of line drives.

This shift in hitting philosophy created a new term – launch angle. Launch angle refers to the angle of elevation of the ball leaving the bat.

This shift in philosophy coincided with the new Statcast sensor system that began being installed in MLB stadiums and was used by all 30 teams by 2015.

Among many other things, the Statcast sensors can calculate the launch angle of every hit. Hitting coaches were soon able to get their hands on data which showed the optimal launch angle for hitting home runs.

The result was a new wave of hitters whose goal was to not hit a line drive but instead to strike the ball from below and create an optimal launch angle that would give them the best chance of hitting a home run.

This approach to hitting does result in more home runs but it also results in far lower rates of getting on base.

If a hitter is trying to square up the ball up and hit a line drive and he succeeds, the result will be a smashing liner. If he misses it a tad and instead gets under the ball, he might still hit a strong fly ball. If he misses and hits on top of the ball a little bit, he might still find a hole with a hard grounder.

By intentionally trying to hit under the ball you reduce your margin for error. Now, hitting too low on the ball results in weak pop-ups or even swings and misses. In certain stadiums and with certain weather conditions, even well-hit fly balls will not always result in home runs.

Strikeouts Are No Longer Frowned Upon

With hitters loving the sexiness of increased home runs on their stat line and coaches giving them the green light to hit for a lower average – teams now looked to stock their lineups with guys strong enough to reach the seats, not necessarily well-rounded hitters.

The stigma around striking out also evaporated. Coaches around the country from Little League all the way up to the Major Leagues had always implored their players to shorten up and just look to make contact when you get behind in the count – citing that anything can happen once you put the ball in play and that nothing good can happen if you strike out.

While this way of thinking is still efficient at lower levels of baseball where the fielders are not good, putting the ball in play weakly is not going to produce good results most of the time in the MLB where the fielders are as automatic as it gets.

Stringing together 3 singles to score a run is difficult and managers began to change their thinking about striking out versus going for the home run at all costs.

Managers began giving their hitters the green light to continue swinging for the fences even when down in the count – figuring that sacrificing a few singles throughout the game is worth it for the increased chance of hitting a big home run and driving in multiple runs with one swing.

Looking at strikeout rates over the past 25+ seasons shows a dramatic uptick in batters returning to the dugout empty handed.

Strikeouts went from being the ultimate embarrassment for a hitter to mere side effects inevitable in the pursuit of home runs.

Tigers great Al Kaline played from 1953-1974, compiling a career .297 average with 399 home runs. Kaline never struck out more than 75 times in one season – a mark that most modern hitters now reach by the All-Star Break.

In the past, teams could put up with having one all-or-nothing slugger – guys like Adam Dunn or Pedro Alvarez who could hit you 40+ dingers with an average barely above .200.

In today’s game, managers are routinely penciling in 3 or 4 “Adam Dunns” into their lineup in the hopes of getting a 3-run homer from one of them.

Comparing Today’s MLB Stats to Those of Past Eras

With batting averages declining across the league, the .300-club is much more exclusive now than it was in the 90s or 2000s.

The MLB was producing 40 or 50 .300 hitters every single season up until the launch angle era began at the end of the 2000s decade. We went from having 42 .300 hitters in 2009 to just 23 in 2010.

Currently two-thirds of the way through the 2021 MLB season there are just 14 hitters with averages of .300 or better … just 14.

Of these 14, I would only call 2 of them power hitters. Nick Castellanos and Vladimir Guerrero Jr. each hit 30+ home runs per year making it all the more impressive that they keep their averages above .300.

Most of the other hitters atop the batting average leaderboards are the league’s surviving contact hitters – guys like Michael Brantley, Adam Frazier, David Fletcher, and Jean Segura.

These 4 all have averages above .310 and combine for only 17 long balls on the season.

In past decades, each MLB team would have a few .300 hitters with many more in the .290s or high .280s. Those days are gone, meaning we should appreciate it all the more when a hitter can keep his average well into the .300 – especially with gaudy power numbers. Guys like Ronald Acuna Jr., Vladimir Guerrero Jr,, and Juan Soto are so impressive because they are hitting for both average and power at a very young age where most hitters are not mature enough to do both.

What Makes a Good Home Run Season This Year?

This next graphic surprised me the most – it is the number of players per season that have hit 35 home runs. As home runs have risen in the 2010s, we would expect the number of 35-home run seasons to also rise, but that has not been the case.

There were many more players hitting 35 home runs in the 90s or 2000s and there are in the 2010s. Even in 2016, 2017, and 2018 – which were top-5 home run seasons all time – there were fewer 35-home run seasons than in years past. So what does this mean?

I interpret these numbers to mean that the average MLB player is more powerful today than they were in the past but that the game’s stars are still right about where they were in the 80s, 90s, or 2000s.

Today a weak hitting shortstop might knock 12 home runs in a season where the same type of player in the 90s would hit 2 or 3. A backup catcher might hit 8 home runs now where he might hit 1 or 2 in 1995.

There were many 35-home run seasons in 2019. Don’t take too much stock in the 2020 numbers as they are extrapolations. The 2020 season only lasted 60 games. There were over 25 players on pace to reach 35 home runs but we all know that most players cannot maintain that pace for an entire season. The 2021 numbers are also an extrapolation, showing the number of players that are on pace to reach 35+ home runs this season.

The top hitters are not any more powerful today than they were in the 80s or 90s. What qualified as an excellent season in 1980 is more or less still the criteria today.

Even though we are setting league records in home runs there has not been a single-player home run or RBI record broken in a very long time.