Offense hasn’t been the same, not since 2009. That year, the average major league team scored 4.61 runs per game. In the five years that followed, the average would drop to 4.38, 4.28, 4.32, 4.17, and finally 4.07 in 2014. It went back up to 4.25 last season and stands at 4.27 this year. This data comes from Baseball Reference. Offense tends to increase as the temperatures go up, so we’re likely to see even more run-scoring than the 4.27 per game we’ve seen thus far.
The 0.18 increase in runs per game from ’14 to ’15 — which amounts to about 875 more runs scored over a full season for all 30 teams combined — didn’t have much mystery surrounding it. Hitters just got non-homer hits slightly more often, and hit homers much more often. On a per-game basis, there were 0.03 more doubles, 0.02 more triples, but 0.15 more home runs. The league-wide .405 slugging percentage tied a high-water mark dating back to 2010.
Teams have been focusing more and more on pitchers who throw hard and miss bats often. It’s been obviously true in the bullpen, with Craig Kimbrel and Aroldis Chapman having made headlines for the last half-decade. But the rise of young starters like Gerrit Cole, Jose Fernandez, and Noah Syndergaard has also played a big role. This year, teams are averaging 8.13 strikeouts per game, which would set by a wide margin a new season-high, surpassing last year’s 7.71 average. In fact, the average strikeout rate has increased every year dating back to 2008. The league-wide walk rate has also increased substantially thus far, at 3.23 per game. That’s up from 2.90 last year, and it’s the highest mark since 2010.
For a few years, many have wondered how to generate more offense. Some have suggested banning the shift. Others have suggested moving the fences in for some ballparks, which ended up happening at Marlins Park. But it mostly has to do with the baseball “metagame,” or how the game’s participants — players, managers, front office personnel, et. al. — use information beyond the rules to gain an advantage. For instance, the current trend is for teams to utilize analytics and defensive shifts. Because those benefit pitchers and fielders more than hitters, this means more of a focus on pitching and defense, which would be described as baseball’s “meta”. Hitters and the teams that rely more on hitters haven’t been as quick to adapt. Until they do, high velocities and shifts will continue to dominate the game.
Perhaps most interestingly — and this doesn’t necessarily indicate anything meaningful — the top four run-scoring teams this season all belong to the National League: the Cubs (6.26), Cardinals (6.17), Rockies (5.50), and Pirates (5.00). Beyond that, only one American League team sits in the top-eight: the Red Sox (5.00) in fifth, followed by the Giants (4.95), Dodgers (4.95), and Diamondbacks (4.85). A National League team hasn’t led in runs per game since the 1990 Mets (4.78). The two obvious reasons for this is that the AL has the DH rule while the NL has pitchers hitting, and that for a while, AL teams (namely the Yankees and Red Sox) had the largest payrolls, which helped attract better players. The talent “meta” now is in player development, not free agency, so payroll is less correlated with talent these days.