Pitch Adjustments Part 1: Working on the Slider

*This series I’ll be running on pitch design will involve a fake pitcher named Joe Southpaw, a mid-level minor leaguer for a big-league organization.

Joe Southpaw is a lefty reliever with a four-seam fastball, a slider, and a changeup that is used sparingly. All are thrown with a high 3/4 arm slot. Release points are pretty close, save for the changeup as Southpaw tends to throw it from a lower arm slot when he becomes fatigued.

The four-seam fastball, which he has great command of, is thrown under a spin direction of 11:10 with a spin efficiency of 95%. The fastball velocity is 94 MPH with a spin rate of 2300 RPM.

The changeup is average at best and Southpaw only uses it as a change of pace pitch to keep hitters off-balance from time to time. Thrown 82 MPH with 1950 RPM, it’s a firm fader that spins around 60 minutes higher than the four-seam; 10:00 with a 90% spin efficiency.

As for his slider (a hybrid variation), there are complications. With an 11:00 spin direction, this hybrid variation has a 55% spin efficiency; Southpaw tends to pull down on the ball more than off the side, thereby creating a lot more rise than sweep. He tends to hang it in the zone and hitters are able to take cuts as if it’s a batting practice fastball. His command of the pitch is also a problem. While Southpaw can hit the zone with regularity, he’s doesn’t locate well.

Its velocity is above average, right around 87 MPH. There’s concern over the imbalance of velocity to spin (2200 RPM) ratio. When Southpaw doesn’t get enough leverage on the seams to create additional spin, his velocity causes the pitch to hang in the zone and become flat.

Here’s a visual on Southpaw’s three-pitch arsenal using the Driveline EDGE tool:

The first thing that jumps out is they are all clustered together in the upper left quadrant of the zone. While the fastball and changeup are fine to reside in their locations, it’s clear (along with the other variables) that we need adjustments to the slider.

We’ll go through some steps of the design phase to determine what kind of changes we want to make. Since we aren’t developing a new pitch per se, just revamping, we don’t have to get into the baseline session too much (that will be for another post).

The main questions we want to answer first are:

1- Should he stop throwing the pitch?
We agree to keep the pitch rather than developing a new one.

2- Do we want to create an attack plan around the hybrid slider?
Since the pitch is getting bad results and the design isn’t great, we agree to not go that route

3- Is it feasible to create more sweep and/or depth?
Possibly; there are a few things to contemplate. If our goal isn’t possible, we might consider changing it to a cutter. The problem with that is his lack of confidence in the changeup and adding a second variation of a fastball would create redundancy in the arsenal.

4- Do we want to increase, decrease, or keep the usage the same?
Decreasing isn’t a viable option because of the mediocre changeup. We decide that if we are able to fix the slider, keeping the usage consistent is the best decision.

Now that we’ve finished the initial assessment, we’ll start by reviewing the visual evidence on the slider.

Using Edgertronic video, we notice that Southpaw gets his fingers too far behind the ball, creating the additional backspin. Grip-wise, everything looks good; ball is deep in the hand and finger pressure appears strong; no need to tinker with that aspect of the pitch.

After reviewing Southpaw’s high 3/4 arm slot, we agreed that its ‘encouraging’ more backspin than side spin. After some bullpen sessions, it’s determined that we don’t want to mess with mechanics; while a slot change might get more of the shape we are going for, he demonstrated a lack of command with a new slot which could take some time to fix.

So, his grip (in terms of pressure and depth in had) is good and we have to work with the arm slot. The next step is changing the gyro orientation of the pitch; adjusting from a more backspin-heavy angle to one that induces more bullet spin.

Adding more sweep to the slider might call for a change in spin direction and its spin efficiency. Southpaw is currently throwing the pitch at 11:00 with 55% spin efficiency. Let’s shoot for 11:40 and, with the proper grip adjustment, we can expect a sizeable change in gyro degree.

To adjust his positional grip on the slider, we’ll have Southpaw adjust his fingers further up on the ball to better leverage the seam and induce more gyro spin than backspin.

Additionally, giving Southpaw mental cues that can help him to pull down on the side rather than behind can help if he has trouble giving the ball the additional bullet spin it needs. Anything that can be said or done to delay pronation and reduce spin efficiency will be helpful.

Pitch one is the hybrid slider Southpaw currently throws and pitch two is more along the lines of what we’re looking for; the sizeable change in gyro degree, 40 minute increase in spin direction, and additional spin to help balance out the velocity. In a best-case scenario, having Southpaw change where he grips the ball and understanding how to better leverage the seams, we could assume that spin rate will increase and/or velocity drops a bit.

Drawbacks to this process could present themselves such as Southpaw’s arm slot, which could be a roadblock in attempting to eliminate the heavy backspin. If that happens it must be decided either turn the pitch into a cutter (not ideal) or drop it and try improving his changeup command and/or start working on a new pitch.

We’ll check back on this pitcher in a later article and see if the change was successful and what kind of results he is getting.