MLB hitters are facing unprecedented challenges this season. The league-wide OPS has plummeted to its lowest point in 10 years and the second-lowest since 1992. This dramatic shift begs the question: What's behind this offensive downturn?
The answer might be simple. Frankly, pitchers are better than they have been. New technology and a better understanding of physics has created more room for development for pitchers in regards to biomechanics and their ability to manipulate the ball. Front offices, scouts, pitching coaches and coaches have recognized two main attributes that increase a pitchers ability to get hitters out: spin and velocity
Spin: The New Frontier
A few years ago we had the "sticky stuff pandemic" where it was exposed that pitchers were consistently using foreign substances like spider tack to get a better grip on the baseball that would coincidentally lead to higher spin rates and nastier pitches. MLB has since enforced rule 3.01, in hopes that it would level an uneven playing field. The opposite seems to have happened.
The stats back up that pitchers are now more dominant than when "Sticky Stuff" was being distributed like sunflower seeds across clubhouses. The Sticky Stuff ban is likely a major reason for this, as pitchers had to naturally improve since they couldn't rely on artificial means to increase their spin rate.
Without being able to increase their spin rate, pitchers shifted their focus to spin efficiency. A 2000 RPM fastball with 80% spin efficiency is less effective than a 1900 RPM fastball with 90% spin efficiency. The reason for this is that the more spin efficient pitch, will see greater benefits from the spin. The 1900 RPM fastball will have more run and rise, making it tougher for hitters to hit. If we're comparing two curveballs with the same spin rate but different spin efficiency, we'll see the more efficient spinning curveball have a sharper break.
The next step tying this together is pitch shape. We know that a ball moves based off the spin, a top-spinning curveball will drop, a back-spinning 4-seam fastball will appear to rise, an east to west spinning pitch will break to the left, etc. Pitchers are custom building their arsenal, looking at their pitches and trying different grips and arm angles to make their pitches spin more efficiently and therefore break more.
The main thing each pitcher has to consider is what is their arm slot, and what pitches synergize well with their arm slot. For example:
- An over-the-top arm angle leads to a high spin efficiency 4-seam fastball, but a less efficient two-seamer. It also leads to a devastating curveball and solid slider, but not a sweeper. Look at Clayton Kershaw, who's dominated with his fastball/curveball and then fastball/slider/curveball combo.
- A side-arm pitcher can naturally have an elite slider/sweeper as well as a sinker, like Adam Ottavino.