Pitch Tunneling: Is It Real? And How Do Pitchers Actually Pitch?

The concept of pitch tunneling is gaining popularity. The idea is that two different pitches fly down the same trajectory long enough to look nearly identical through the point when a hitter must decide whether, or not, to swing. If pitches thrown back to back travel down this same “tunnel” long enough, a hitter won’t be able to tell them apart until it’s too late. There also seems to be some confusion about the idea itself – is it mechanical, in which pitchers should change their deliveries to improve tunneling? Or, is it simply a matter of pitch sequencing? And, if tunneling is only a sequencing concept, are, and should, pitchers be using it? Let’s find answers to these three questions.

Part 1: Pitch Tunneling Is Not a Mechanical Concept: A Distinction Without a Difference

At Baseball Prospectus, Jeff Long, Jonathan Judge and Harry Pavlidis have identified the “tunnel point” as 23.8 feet before home plate. The goal is that two pitches, thrown back-to-back, would fly through the same narrow tunnel, basically making them appear to be the same pitch.

If a pitcher can’t control his body well enough to precisely repeat his delivery, then his pitch tunneling ability suffers – the hand will be in a noticeably different position at the release of every pitch. And for a pitcher who repeats his delivery exceptionally well, like Jon Lester does, the pitches he throws will look very similar for as long as possible. Again, if you repeat your delivery very well, tunneling will happen on its own if you pair pitches with the same starting points. If you don’t, it won’t. Pitchers don’t need to practice throwing pitches through small hoops 20ish feet from the plate. Rather, they simply need to practice pitching with a focus on doing the exact same thing with their body on every single pitch.

If it is unclear to you whether pitch tunneling is a physical concept worthy of its own term, let me assure you that it is not. The main thing a pitcher can control is the repeatability of delivery, which in turn directly affects release point. Coaches have always emphasized to pitchers: Practice repeating your delivery! If you want to throw more strikes, learn to repeat your delivery!

Repeating ones delivery means that all of the following variables are held constant between pitches. The following are well-controlled by pro pitchers, and, loosely controlled by amateurs.

• Delivery footwork
• Tempo
• Stride length
• Stride direction
• Actual velocity
• Intensity
• Finish and follow through
• Location on the rubber

Having the proper conditioning to prevent fatigue is also a factor.

From a mechanical perspective, we have a distinction without a difference – “repeating the delivery” is all that is required to physically create tunneling. A pitcher who repeats his delivery sets the stage for all pitches to tunnel provided they use the same starting point, the same initial trajectory. And, to shed light which is explained in the next section. Whether he chooses to do this, however, is another story, as this concept hinges on pitch selection.

Part 2: How Pitchers Create Tunneling: Focal Point = Tunnel

If a pitcher repeats his delivery, then the flight of each pitch, to each location, is essentially predetermined by physics. To make them take the same tunnel, then a pitcher would need to pair pitches based on where they start, not where they end. The deviation from a tunnel, for a pitcher who repeats his delivery well, will then only come from deviations in starting location, or focal point (used interchangeably). As a pitcher, one of the most important concepts I learned, and now teach, is how to command my “moving” pitches. For lack of a simpler term, I’ve been calling it pitch vectoring, which stems from a high school physics lesson.

Your goal is to swim straight across a flowing river. If you swim exactly toward point B, from point A, would you make it precisely where you intended? The answer is no: the current would take you with it, so that you would end up on the other side but down-river a bit. Your initial heading, your starting point, the point on the opposite river bank you focused on reaching, would not be where you ended up. Most young pitchers, when asked, have no idea how they locate their curveball or slider. “Where do you look?” I ask. “The mitt.” They reply. If you ask a pro pitcher what happened on a specific pitch that didn’t go well, he’ll often respond, “Well, I tried to start it on the inner half…”

If a pitcher looks at the mitt and wants his curveball to end up at the mitt…how does he account for the 14 inches it breaks? He can’t, and the only way a pitcher can reliably control and locate his moving pitches is if he establishes a deviation point or focal point for each pitch. Sinkers and two-seamers also are thrown within this framework, but aren’t traditionally referred to as breaking pitches.

For a four-seam fastball, where we look is where the pitch ends up – it becomes the pitcher’s visual set point. So, for a curveball to hit the catcher’s target, a pitcher will typically “start” it at the catcher’s forehead. He’ll then focus his eyes, point his front shoulder, and finally move his chest, then hand, toward that focal point. That, in a sense, is how pitchers actually locate their pitches. The focal point changes depending on the break of the pitch. This sounds like pitching 101, but it’s not; I wasn’t taught this until I was 21 years old, three years into my Division-I baseball career. The illustration below shows the pitcher’s point of view and how his entire arsenal would break out from one fastball starting point, or tunnel. Each pitcher’s breakout would vary depending on what they throw and how much each pitch breaks. The takeaway here is that a pitcher can’t possibly tunnel two different pitches that end up in the location – he can only start them at the same focal point, intending them to end at different points.

Part 3: Is Tunneling Considered in Pitch Calling?

Starting a pitch at the same focal point is the same as starting it down the same tunnel. This is the only thing a pitcher truly controls, the action item of this whole pitch tunneling concept, which leaves a pitcher with only predetermined options. To throw a high fastball and then follow it up with a “tunneled” slider leaves us with, well, a slider that will end up mid-thigh on the outer half (shown in the previous illustration). In that example, we must remember that good tunneling is not the goal: getting outs is the goal. Throwing mid-thigh sliders won’t, over the long haul, help that goal, even if they look like fastballs at first. The right pitch to choose depends on the pitcher’s arsenal, strengths and weaknesses, situational context, and more.

You might be at home thinking, plan the fastball better, so that then the next pitch fits into that tunnel more effectively! That’s a good thought, but if you were to plan out each pitch before seeing how the hitter reacts, you’d be very ineffective. High-level pitchers do start each at-bat with a plan, but it evolves with each pitch according to the following:

• Did I hit my spot?
• Ball or strike?
• Swing or no swing?
• Swing and miss or foul?
• How did he foul it off?
• How did he miss? Early or late?
• How did his swing look?
• How did he stride?
• If an off-speed pitch, was he on his front foot?
• How was the quality of the pitch I threw?

Pitches Are Chosen for Their Expected Outcome

Let’s look at a common example. Think of a typical, hard-throwing late-innings pitcher with an upper-90s fastball and slider. These hard-throwing pitchers will usually manufacture strikeouts with two pitch variations:

1. A buried (in the dirt) slider
2. A high fastball

If the game is on the line and he has two strikes on a hitter, good money is on one of those pitches being thrown. The problem, though, is that these pitches will never be in the same tunnel. Consider the following two diagrams that show the different focal points, or tunnels:

The high, strikeout fastball (letter-high) will never look like the low, strikeout slider that breaks into the dirt – a pitcher has no way to get them in the same tunnel. Yet, both pitches get high percentages of swings and misses because when thrown in those locations, hitters are often left with a zero-sum outcome – take the pitch for a ball, or swing at it and almost definitely miss. A pitcher with two strikes on the hitter would never choose to follow up a high fastball with a mid-thigh slider; he’d always follow it up with a slider down, where it would get the desired result. The two wouldn’t tunnel, but it wouldn’t matter because the hitter still wouldn’t feel comfortable taking either in a two-strike count, nor would be find it easy to lay off. The pitcher would choose either pitch, even without a tunneling effect, because he likes the expected outcome.

So, Does Tunneling Work?

How effective are tunneled pitches? I suggest reading this excellent article by Jon Roegele here at THT. His analysis shows how pairs of tunneled pitches, which he refers to as “in the band,” get a higher-than-average swing-and-miss percentage.

The closer consecutive pitches are to one another at the swing decision point, the less distance apart they need to arrive at home plate to generate higher than normal swing and miss rates.

There’s no doubt that there’s legitimacy to this concept; when we pair pitches that share a tunnel, hitters get fooled, and whiff more often. The problem, though, is in implementation. Pitchers tend to choose pitches, hedging risk, on expected outcome. Sometimes tunneling aligns with this, sometimes it doesn’t.

If a hitter has a slow bat, opposite-field approach, or a long swing, a smart pitcher might throw him fastballs inside the entire at-bat, until the hitter is out or proves he can adjust. This doesn’t run counter to the effectiveness of pitch tunneling, just illustrates that trying to choose pitches for tunnel effect often comes secondary to pitching to an expected outcome. For this opposite-field hitter, every inside fastball has an expected outcome of either weak contact or no contact. Deception isn’t required – all pitches will look the same because they are the same, but it doesn’t matter. As a teammate of mine once put it, “hitters often know what pitch is coming but still can’t do anything about it.”

Additionally, pitchers choose pitches that may appear to be chosen based on tunneling, when in fact they’re paired for expected outcome.

For example, fastball-curveball pitchers don’t necessarily pair high fastballs with curveballs because they look the same. Rather, they pair them because both pitches are swing-and-miss pitches. This is an important distinction. The only fastball on which a pitcher will reliably get swings and misses is a high fastball. All other fastball trajectories either look like a ball out of the hand, or are in the strike zone just enough to be put in play. The one location where a pitcher feels safe with a straight fastball is up. Everything else is left to chance. With two strikes, I’ve thrown five fastballs in a row at the letters, knowing that if I hit that spot, I’ll get a strikeout, or at worst a pop-up, sooner or later. No other location has that power.

The letter-high fastball is often paired with a curveball that bounces. But, even if we assume that the high fastball and the bouncing curveball have the same tunnel (they likely don’t, as pitchers usually start a bounced curveball at the catcher’s chest), those two in the pair are both chosen for their zero-sum outcome – ball, or strikeout. They both have that same purpose, regardless of what deception they might produce. If I was hunting for a curveball strikeout, I’d never throw it in the strike zone intentionally to pair with a high-fastball’s tunnel. Rather, I’d throw it so it bounced on the point of the plate, because that gives me the best expected outcome. Most high fastballs will share a tunnel with a curveball that breaks into, not out of, the strike zone. So, the pair doesn’t go both ways.

It’s also advantageous to not chase swings and misses at all times. In many cases, pitchers will go out of a tunnel to induce contact and end an at-bat quicker. An example a fastball that ends up low and away, followed by a slider that ends up the same spot. A slider that tunnels would break off the plate, which would more likely induce a swing and miss. But, sliders that break to the outside corner are difficult to hit hard, and a pitcher might, in this case, go out of the tunnel intentionally to induce weak contact to keep his pitch count low.

Conclusion

Assuming a pitcher can repeat his delivery well, pitch tunneling is most relevant as a concept of pitch sequencing. Though a pitcher’s ability to use tunneled sequences may increase deception, pitchers select sequences based on expected outcomes. If the expected outcome of the pitch is the best of all considered, then that is the right pitch, regardless of whether it follows the previous pitch tunnel, or even if the hitter is expecting it. Though pitch tunnels are intriguing and can certainly aid pitchers in making good pitch-calling decisions, expected outcomes will likely remain the gold standard.

References & Resources

• Baseball Prospectus, Pitch Tunnel Pair Statistics
• Jeff Long, Jonathan Judge and Harry Pavlidis, Baseball Prospectus, “Prospectus Feature: Introducing Pitch Tunnels”
• Jon Roegele, The Hardball Times, “The Effects of Pitch Sequencing”
• Darius Austin, Baseball Prospectus Wrigleyville, “Jon Lester and Pitch Tunnels”
• Daniel Schwartz, FanGraphs, “The Importance of Release Point Consistency”
• Eno Sarris, FanGraphs, “What Can Hitters Actually See Out of a Pitcher’s Hand?”