5 trends to keep an eye on in 2017

Homers, strikeouts, relievers are dominating the game

March 26th, 2017

Nothing has been decided in the baseball world this year, but one thing is for sure: The 2017 season won't resemble anything close to the game your grandparents -- or even your parents -- watched when they were growing up.
This sport is constantly evolving, and teams typically embrace new ways to play the game every five to 10 years. But the specific battle between pitchers and hitters, always a focal point of baseball, has really taken center stage in our current era. Pitchers are becoming more specialized and, in turn, more efficient at limiting contact. In response, hitters are swinging for the fences more than ever before.
In addition to all the wins, losses and drama soon to unfold, here are five statistical trends about today's game worth keeping an eye on in 2017.
1. The home run is back -- and bigger than ever
As it turns out, fielders are still flat-footed on many other balls that actually are put in play. Last season was partially defined by hitters' all-or-nothing approach, and when they connected, they cleared the fence at a historic rate.
One way we can measure that progression is by examining how many contact plays (i.e., any plate appearance that doesn't end in a walk, strikeout or hit by pitch) resulted in home runs. As shown in the chart below, big league hitters homered on a higher percentage of batted balls than any other year in the Live Ball Era (1920-present).

A natural increase in homers over the past 100 years makes sense; we're nearly a century removed from Babe Ruth transitioning to a full-time position player. But hitters tallied 1.2 percent more home runs on batted balls in 2016 than they did just two years ago, and they allocated a higher percentage of their hits for homers last year than at any point in the perceived Steroid Era of the 1990s and early 2000s.
As hitters swung for the fences last season, their teams appeared to be more content to wait for the big blast to bring in runs. A staggering 40.2 percent of all runs scored in 2016 came off homers, a new all-time mark. That effort was led by the Mets, who generated 51.1 percent of their scoring off the long ball to set a new National League record.
2. Fewer free passes available
Intentional walks will have a completely new feel this year when managers simply signal their decision to the umpire instead of having their pitchers send four lazy tosses to the catcher. But while that change might shave time off the length of game, the truth is there may be less need to impose it now than at any time in recent memory.
The high strikeout rates referenced above and, perhaps, an analytical change in the tactics of big league managers, has eroded the use of intentional walks. Only 932 of them were issued last year in the Majors -- the fewest over any full season since 1962 -- and the total has diminished over each of the past five seasons. With an average of only three to four intentional walks given out now over an entire night of games, eliminating those four pitches might hardly move the needle.

3. Grease up the bullpen door
Notice more pitching changes last year? Your eyes did not deceive you.
Relief pitchers made roughly five percent more appearances league-wide in 2016 than they did just five years before, and nearly 20 percent more than they did at the start of the millennium. Furthermore, we're seeing a greater variety of relievers than ever; a total of 7,869 players pitched at least one inning in relief last year, easily the most in history and over 1,000 more than at the start of this decade.
The expectations of the starter continue to evolve. MLB pitchers averaged roughly 5 2/3 innings per start in 2016 -- the lowest rate in history -- and combined for fewer than 100 complete games for the first time in history. Last season, the Dodgers had 83 games in which their starter did not reach the sixth inning, and yet they won nearly half of those contests. Then in the postseason, the Indians came this close to winning it all while their starters averaged only 4 2/3 innings per game.
Indeed, starters who can routinely go deep into the later innings are getting fewer and farther between: Only five pitchers who qualified for last year's ERA title recorded quality starts in at least 75 percent of their outings, the fewest since 2009.
4. Don't bunt. Hit dingers.
It's more than just a T-shirt slogan; it's a growing philosophy in the game. Big leaguers laid down only 1,025 sacrifice bunts last year, the fewest in modern baseball history. And 2016 was not an aberration, as the total number of bunts has steadily declined in each of the past six seasons.
Many managers are largely eschewing the bunt as sabermetrics keep proving that it reduces the chance of a big inning. However, with defensive shifts becoming more like the norm, often leaving the third-base line open for left-handed hitters, a well-placed surprise bunt could be worth it every now and then. Even , the unofficial face of the "never bunt" movement, used a bunt to get on base last Sept. 28.
5. The Live Ball Era is getting less lively
One of the bigger stories this offseason involved Major League Baseball's formal proposal to the MLB Players Association to raise the lower part of the strike zone to the top of the hitter's knees. Why the change? As umpires have incrementally called more and more strikes below the defined lower boundary of the strike zone, the advantage has swung toward the pitcher -- and the action on the field has declined.
A bigger strike zone means more strikeouts. In fact, MLB hitters have set new all-time records for strikeout rates in each of the past nine seasons, peaking in 2016 when they punched out in 21.1 percent of their plate appearances. Combine that with a walk rate that consistently hovers between eight and nine percent, and we saw more inaction last year than at any other point in the past 100 years.

One way to improve pace of play -- something Commissioner Rob Manfred has identified as a primary objective -- could be to reverse this trend and induce more batted balls in play. Tightening up the strike zone would help baseball achieve that.
Will these trends continue to veer to the extreme, or will we return to more of a status quo? Opening Day is almost here. Stay tuned.