Designing a Slider
A slider is a pitch with lateral spin, some top or back spin, and sometimes gyrospin (bullet spin). This pitch has a wide range of uses, from moving like a cutter to moving like a sweeping curve.
Obviously, we want to miss bats, and the slider is, on average, the most effective pitch for that. Some of the best in the game have sharp and late breaks and do a great job of keeping hitters off balance.
Spin Axis Goals:
Depending on what your goals are for the pitch, your ideal spin rate will change. For a slider with the most amount of glove side movement, a 9:00 spin axis or 3:00 for a lefty. When trying to generate a slider with more vertical depth, add more top spin to push the axis below 9:00 or 3:00. It is important to understand your other pitches well so you can find which axis will compliment them the best.
Spin Efficiency Goals
For that maximum arm side movement, a 35% efficiency is your goal. With a lower arm slot, a gyroball can be used effectively. A gyroball would be a slider with gyroscopic spin at 0% efficiency. At 0%, the ball has no magnus force acting upon it because there is no top or back spin. When this happens, the ball will have no movement outside of the effect of gravity. Regardless of your goals, having consistency in your efficiency will help you have pinpoint control and advanced usability in your pitch.
Now I want to discuss three of the best sliders in the game and what makes them different. For this we will be looking at Adam Ottavino, Patrick Corbin, and Chris Sale.
All three of these guys have varying data. All of their spin rates are different, the shape of their sliders are different, but what they have in common is their tilt. Each of them can consistently hit their ideal spin axis. Partick Corbin has the lowest average horizontal movement of the three, but you may be surprised to learn that he has them beat in swing & miss %, being nearly 20% higher than league average. A big reason behind this is his higher arm slot. When a pitcher has an uncommon arm slot, it's harder for most hitters to adjust. Each of these pitches are effective and difficult for hitters to square up, so this goes to show that there is more than one way to create a good slider.
Throwing a slider most often requires a pitcher to have his pointer and middle finger on the outer half of the baseball, mostly looking like a 2seam grip that is placed off to the side of the ball. It is important to note that the movement comes from the ball rolling off of your pointer finger. Remember, a slider has more lateral spin than back or top spin that creates bullet-like spin. You may want to cock your wrist towards your thumb, depending on your arm angle, while creating a wrist-snap upon release.
Below is an example of the most popular way to grip a slider. The key is to feel the ball rolling off your pointer finger.
There are plenty of other ways to grip this pitch, but like most other pitches you can tweak your finger placement if your arm slot requires you to. That is why having a true understanding of what the ball is supposed to be doing as it travels to the plate is vital to pitch design.
As you can see, both my middle and pointer finger are making contact with the seam. This is because when I snap my wrist at release, the grip on the seams will help me generate a little more spin. This pitch needs to spin like a bullet with a slight backspin, and those of you who can effectively replicate your arm and hand movements at release will have the most success and consistency.
Be prepared to work hard to maximize the benefits of this pitch if you want to have one just as devastating as Otttavino, Sale, or Corbin.
Next week we will start a discussion on Changeups!