Final 2019 Pitching Trends

Yesterday, I shared and discussed a plethora of hitting metric trends from 2015 to 2019. More strikeouts, more fly balls, and more home run power are the obvious trends. Now let’s look at how the early 2019 pitcher trends I discussed in mid/late April ended for the season.

Gosh, ERA shot up to 4.51 for the season! I still remember the days when I wanted no part of a starting pitcher projected for an ERA over 4.00. While I still wouldn’t choose to roster one, they could actually still earn some positive fantasy value (depending on league format, of course), whereas it would have been almost impossible to do so in years past. It also makes the guys still posting sub-3.00 ERAs that much more valuable. Interestingly, WHIP hasn’t spiked like ERA has. There’s an easy explanation for that — because WHIP treats all hits equally, it isn’t affected as much by the record rate of home runs, whereas it’s clearly inflating pitcher ERAs.

Strikeout rate just keeps on rising. In fact, if you run all seasons we have data for going back to 1871 and sort by strikeout rate, you’ll realize the amazing — that we have set a new strikeout rate record every single season since 2008. Since that year, strikeout rate has increased every season, and every new season brings a new record. That’s nuts! When does it end? One of these seasons has to represent a peak that we stabilize at, right?

While walk rate has jumped since 2015, we have stabilized over the last three seasons. This rate doesn’t sit at any extreme compared with history though. As a result, K%-BB% has also increased nearly every single season since 2009, with a step back in 2015 the only exception.

Shocker, SwStk% keeps going up. That’s obviously behind the strikeout rate increase. Pitchers are generating more whiffs, which are leading to more strikeouts. Strike rate has been relatively stable since 2016.

Death to the sinker! That’s one of the main takeaways from this table. Though the sinker is best when you need a grounder, it typically generates the lowest whiff rate. Unless your infield defense is elite, or your desperately need a double play, it would make much more sense to throw a pitch with a far greater chance of inducing a swing and miss. Remember, strikeouts are guaranteed outs, whereas a ball in play goes for a hit 29% to 30% of the time, and may even fly over the fence!

Changeup usage is up marginally, while slider usage has gone through the roof. The average slider generates the highest whiff rate (the splitter actually might be higher, so excluding those), so that nicely matches up with the overall increase in SwStk% and strikeout rate. That, my friends, is one of the biggest drivers of the increasing strikeout rates. So it’s really just pitchers swapping out sinkers for changeups and sliders. Guess what? Fly balls are up too, which also matches with the data here, as fewer sinkers should result in fewer grounders.

Yup, average fastball velocity continues its upward march. Oddly, the cutter hit a five year velocity low. Matching the four-seam velocity increase is the sinker. Even though pitchers are throwing it less often, they are throwing it harder! To keep up with the increased fastball velocities, pitchers are also throwing their changeups harder, a mark that has increased each season since 2015. Slider usage may be increasing, but check out the velocity trend! It hasn’t changed since 2015, and is up just 0.1 MPH since. That’s pretty crazy.