If there's a word to describe postseason baseball, it's probably this: More.
More attention is paid to each game, obviously, and there's more pressure. More thought goes into every decision, because more is riding on every choice. That's all obvious, of course, but there's something else the bright lights of the postseason do. They massively amplify the trends that shape the game we see during the regular season.
Think about the way baseball functions during the months preceding the playoffs, and then what happens in October. We've seen the increasing influence of relief pitchers taking over the regular season; in October, we see more of them. Regular-season baseball has largely become about home runs and strikeouts; in October, we see more of each. The average fastball is thrown harder in the playoffs. The average launch angle increases in October. Balls hit in the air are hit harder in October. Everything is more.
It's still baseball. It's just baseball turned up to 11.
This is all connected. This is the confluence of several different trends, all accelerated because of the way the postseason is set up, with only the best teams using only their best players, and with a flexible schedule that allows for such things. None of these things happen independently of everything else.
Nowhere, perhaps, is that more noticeable than with what's termed the "Three True Outcomes," a term used to describe strikeouts, walks and home runs, so named because, in theory, they're the three main outcomes that the pitcher and batter control entirely, without input from fielders. Another way to think about that would be to describe it as plate appearances that don't end with a ball in play, which, as you know, is a number that's been increasing in the regular season for many years.
In the postseason, the rate of plate appearances that end in one of the three true outcomes is ... more. Of course it is.
There's no shortage of reasons, theories and suggestions as to why the three true outcomes have increased in the Major Leagues in the regular season over the years. (Let's be honest here: While the trend shows an increase in the "three" true outcomes, it's really about the big two, strikeouts and home runs. Walks have held steady in the eight percent range, with minor fluctuations, for decades.)
So far as strikeouts go, there are a few reasons, starting perhaps with the fact that batters simply don't feel as much shame about swinging and missing as they once did, particularly as the importance of batting average continues to drop and the popularity of other more-inclusive stats that account for the value of drawing walks and hitting for power -- like OPS or wOBA -- go up.
You've heard all sorts of stories about how, say, Phil Rizzuto struck out only 27 times in 630 plate appearances in 1951, a minuscule 4.3 percent whiff rate. That's just a fraction of the 30.7 percent strikeout rate Aaron Judge put up in 2017 while striking out 208 times, a number that would be jaw-dropping decades ago. Of course, that year Rizzuto also had a slugging percentage 281 points lower than Judge did last year, and Rizzuto had a 92 OPS+, making him eight percentage points below the league average of 100. In 2017, Judge had a 170 OPS+, second only to the great Michael Trout.
The strikeouts didn't matter as much as the slugging did. In 2017, the top eight teams based on slugging percentage all made the playoffs, but only three of the dozen best strikeout teams did. It's nice to make contact. It's better to make good contact.
Hitters know this, and so do pitchers. As Judge showed, it's possible to be a very good hitter while striking out a lot, yet the inverse -- being a very good pitcher without missing bats -- is rarely true. The incentive structure is misaligned; if pitchers require strikeouts and hitters don't care about supplying them, well, of course strikeouts will increase, so long as power comes with it.
There are far more tangible reasons than that, however, for the increase of strikeouts and home runs in the sport, both in October and in the months preceding it. As we over-simplify to tick these off, realize how many of the underlying causes then increase in October, fueling the further increase of the three true outcomes.
Strikeouts are up because ...
... velocity is up.
This is the most obvious reason, because it's probably the most correct reason. In the 2008 regular season, the average four-seam fastball was 91.9 mph. That year, only 16 pitchers (among those who had thrown at least 100 four-seam, two-seam or sinking fastballs) averaged 96 mph. In 2017, that 91.9-mph average had jumped to 93.2 mph, and 62 pitchers averaged at least 96 mph, nearly four times as many. It's an incredible jump in just a few short years.
In the postseason, velocity is up even more. In 2017, the average four-seam October fastball was 94.5 mph, more than a full mile per hour above what it was in the regular season.
So where does that velocity come from?
There are more relievers than ever.
The extra heat is from better training for better athletes, certainly, but also from the understanding that no one is being asked to go nine innings anymore. It's a "grip it and rip it" sport, and that was true even before you heard the terms "bullpenning" or "the opener." It's a lot easier to find velocity in shorter stints, which in turn fuels part of the "third time through the order" avoidance that gives managers incentive to prevent starters from pitching deep into games.
In the five regular seasons from 2013-17, starters struck out 19.7 percent of hitters they faced. Relievers struck out 22.4 percent. This isn't rocket science, really. This is why you see more relievers now, and this is why the share of hitters faced by a starting pitcher keeps on dropping.
In 2011, starters faced 67 percent of hitters. By '15, it was only 65 percent, dropping to 63 percent in '16, 62 percent in '17 and nearing 60 percent in '18.
In the playoffs, starters haven't faced more than 65 percent of batters since 2010. Last October, starters faced only 53 percent of hitters, the lowest in the divisional era, and we're nearing a 50/50 split. We might see it this year. In October, it's a game of bullpens.
It's not hard to see why. In addition to the better outcomes, the expanded postseason schedule, with extra days off, allows managers to rely upon their relievers more than they do in the regular season. The 2017 World Series champion Houston Astros, for example, had 10 days off in the midst of 18 postseason games, only twice playing three games in a row. They had 20 scheduled days off, including the All-Star break, during their entire 162-game regular season.
But October home runs are up, too, because...
As the results of a scientific panel assembled by the Commissioner's Office earlier this year showed, reduced drag on the ball may be the root cause of some of the record-setting home run totals we've seen in recent years, but that doesn't explain the difference between the regular season and October.
In the 10 regular seasons from 2008-17, we saw one home run every 33.5 at-bats. In the postseason, that number dropped to one every 32.1 at-bats. Looking only at last year, there was a home run once every 27.1 at-bats in the regular season, and one long ball every 24.1 at-bats in October.
Why are there more home runs in October? It could be because the prospect of facing the best pitchers in the sport, or well-rested relievers, makes the idea of stringing multiple hits together too daunting, so hitters swing for the fences instead. (This would also explain some of the higher strikeout numbers.) That's just a theory, however. Let's look at the numbers.
Launch angle is up.
You've surely heard the term launch angle by now, as it's become one of the most popular terms since Statcast™ came online in 2015. It is, quite simply, a measure of the vertical angle that a ball is hit coming off the bat, measured in degrees. The Major League average launch angle has increased each year, from 10.1 degrees in '15 to 10.8 in '16 to 11.1 in '17 to nearly 12 degrees as '18 nears its end.
That may not sound like a big difference, but 2015 had over 3,500 grounders more than '17 did. It's a big deal.
In the postseason, launch angle has been up even more, by an average of a full degree each year. In 2017, for example, after the league saw a 45.3 percent ground-ball rate during the regular season, that dropped to 44 percent in October. In '16, the discrepancy was even larger: 46.1 percent in the regular season, and only 43 percent in the postseason.
Hard-hit liners and fly balls are up, too.
Not only does the ball get in the air more in October, it gets hit in the air harder, which is a big deal. Statcast™ defines a hard-hit ball as one on which the exit velocity was at least 95 mph, because that's where the most damage occurs. In 2017, the league hit .639 with a 1.538 slugging percentage on hard-hit flies and liners. You see why hitters want it.
In each of the past three postseasons, the hard-hit rate on flies and liners has exceeded what it was in the regular season. In 2015, the 43.5 hard-hit rate on flies and liners jumped to 48.2 percent in the playoffs. In '16, it went from 44.5 percent to 47.5 percent. In '17, it was up from 44.6 percent to 46.4 percent.
Remember that for hitters, two of the three outcomes are good, and they can live with the negative one if they're getting enough of the first two. That's been a driving force behind one of baseball's largest changes over the past 15 years or so. In October, that happens more. In October, everything happens more.