Be On-Time This Preseason: The Flat-Ground Key for Pitchers to Protect the Throwing Arm and Accelerate Smoothly
Preseason is not just about “getting your arm in shape.”
It’s about building a delivery that lets your arm show up on time—and accelerate the way a healthy arm is supposed to: smoothly.
Because in our DVS Injury Risk Model, one of the strongest predictors of increased throwing-arm injury risk starts where most people rarely look:
at the ground.
Not just because it impacts health, but because it directly influences a pitcher’s ability to execute pitches consistently once games begin.
The Definition That Changes Everything
I define being on time as this checkpoint at foot strike:
The throwing forearm and the spine are within 10° of parallel.
When that happens, the throw feels quieter. Cleaner. Repeatable.
When it doesn’t, the arm usually has to rush to catch up. And rushed arms don’t just miss location—they wear down faster.
Flat Ground Is Where You Earn It
Most of a pitcher’s preseason volume happens on flat ground, not a mound. So if you want to be on time in games, flat-ground throws are where you earn it.
Not by throwing more.
By throwing with a purpose: to rehearse the sequence that will hold up when intent rises.
I call this scaling energy—building intensity while preserving the timing and pathway that protect the arm and sharpen execution.
Match the Slope (Even When You’re Not On One)
Here’s the detail most pitchers miss during preseason throwing programs:
When you’re making throws on flat ground, you still need to match the slope.
You’re not on a mound—but you should visualize that you are.
That simple intention changes the quality of the move. It enhances Mass & Momentum, improves the flow of the sequence, and helps the arm accelerate on a smoother path.
Flat ground can easily turn into a “stand tall and throw” environment. Matching the slope keeps you moving with direction, keeps the pelvis turning on time, and reinforces the same downstream outcome you want on the mound:
an arm that arrives on time and accelerates smoothly.
Being On Time Starts With the Rear Foot
Being on time doesn’t start with the arm.
It starts with how you set the rear foot.
If the rear foot isn’t aligned and pressured correctly, the lower leg and hip don’t sequence well, the pelvis turns late, and the arm is forced to speed up to compensate.
The cue is simple:
Rear foot square to the rubber (toe can be slightly turned inward)
At the top of knee lift, roll the ankle toward the target
When that pressure is right, the tibia—and eventually the rear hip—can sequence so the pelvis begins rotating earlier, not later, creating a clear runway for upper body mass and the throwing arm to arrive on time.
A quick reminder: earlier pelvis rotation does not mean the lead leg flies open like a gate. When it swings open early, it usually signals the rear hip didn’t truly carry the move.
What We Measure in DVS X-Ray: Mass & Momentum (MM)
Inside DVS X-Ray, we quantify this early sequencing as Mass & Momentum (MM).
We score it 0–4.
And the relationship is strong:
Every 1-point increase in MM reduces injury risk by ~24%.
So yes—this is about mechanics.
But it’s also about what mechanics produce: timing, efficiency, and durability.
MM is a way to standardize what great movers do naturally: they create energy early with the body, in a way the arm can transfer.
The Arm Tells the Truth: Acceleration Smoothness
Now that Arm Impulse Metrics are integrated into DVS, we can connect early inputs to arm outputs.
One metric tells the story quickly:
Acceleration Smoothness.
It should trend closer to 1.00.
Closer to 1 = the arm is accelerating on a smooth, efficient path
Lower values = the arm is often rushing, creating a more abrupt acceleration pattern into release
And here’s the important part:
Getting on time is what allows acceleration to become smooth.
When the arm arrives on time, it doesn’t need to “help” the throw early.
The body creates the energy. The arm transfers it.
That’s how the shoulder and elbow survive the season.
The “Gateway” Moment: Where Timing Is Often Won or Lost
A lot of pitchers think timing is a late-delivery problem—hand break, arm swing, release point.
But the real window often happens earlier, at what we refer to as the Gateway: the transition point where the lower half commits directionally and the pelvis is either set up to turn on time… or forced to turn late.
If the rear foot and pressure aren’t set, the tibia doesn’t sequence the way it needs to. The rear hip doesn’t internally rotate efficiently. The pelvis stalls.
And when the pelvis stalls, the arm speeds up.
What the Video Clips Show
The clips attached are flat-ground examples of this sequence showing up in real time:
Rear foot alignment + pressure sets the move
The pelvis begins turning on time at the Gateway
The arm rotates up earlier
At foot strike, the arm is on time
Acceleration Smoothness climbs closer to 1 as the throw becomes more efficient
It’s subtle. But the difference is loud if you know what you’re looking for.
A Simple Daily Checklist for Your Preseason Throwing Program
Use this checklist on flat ground as you gradually build intensity:
Set rear foot alignment + pressure
Sequence the rear leg/hip so the pelvis turns on time
Keep the stride directional to the target
Arrive on time at foot strike (forearm + spine near parallel)
Let the arm accelerate smoothly (Smoothness trending closer to 1.00)
This is how you scale energy without losing your delivery.
Across the last 2,000 initial evaluations inside DVS X-Ray, the average MM score is 1.4. That doesn’t mean pitchers aren’t talented. It means a large percentage are building their season on a foundation that makes them late or early, and forces the arm to solve problems it was never designed to solve.
The Bottom Line
Preseason is your one window to change the outcome.
Don’t just “get your arm ready.”
Get on time, all the time. And let the arm accelerate the way it’s supposed to: smooth, efficient, sustainable.
P.S. Want a second set of eyes on your preseason program? If you’re not sure your arm is truly “on time,” or if your flat-ground work is actually translating to the mound, send me an email to review a few clips and your plan.
📧 justin@dvsbaseball.com. Subject: Preseason Timing
How the M.V.P. Program Fits
This is exactly what we build inside the DVS M.V.P. Program—a step-by-step training pathway that helps pitchers improve timing, scale intensity, and sustain execution without forcing the arm to “catch up.” If your preseason plan is missing structure, MVP gives you the weekly framework to connect what you’re doing on flat ground to what needs to show up on the mound.
Learn more about the M.V.P. Program → (link)
FAQ
What does “on time” mean for pitchers?
In this article, “on time” means that at foot strike the throwing forearm and spine are within ~10° of parallel, allowing the arm to accelerate without rushing.
Why are flat-ground throws so important in the preseason?
Because most preseason throwing volume happens on flat ground. Flat ground is where you can rehearse sequencing and timing so that when mound intensity rises, the arm still arrives on time.
What does it mean to “match the slope” on flat ground?
It means visualizing you’re moving down a mound even when you’re on a flat surface. That intention improves direction, enhances Mass & Momentum, and helps the sequence flow into smoother acceleration.
What is Mass & Momentum (MM) in DVS X-Ray?
Mass & Momentum (MM) is DVS X-Ray’s measurement of early sequencing from the ground up. It’s scored on a 0–4 scale and reflects how effectively a pitcher creates energy early with the body that the arm can transfer.
What MM score should a pitcher aim for?
The goal is to improve your MM score over time. In our model, each 1-point increase is associated with ~24% lower injury risk, so incremental gains matter.
What is Acceleration Smoothness in DVS X-Ray?
Acceleration Smoothness is an Arm Impulse Metric that reflects how efficiently the throwing arm accelerates into release. Values closer to 1.00 indicate a smoother, more efficient acceleration pathway.
Why should the Acceleration Smoothness trend closer to 1.00?
Because it often signals the arm isn’t rushing or creating abrupt surges of acceleration into release—patterns that are harder to repeat and can be harder to tolerate over a season.
What typically causes low Acceleration Smoothness?
Low smoothness often shows up when the arm is late and has to “catch up,” creating a more abrupt acceleration pattern into release. It can also appear when intent rises before sequencing is stable.
Does earlier pelvis rotation mean the lead leg should fly open?
No. Earlier pelvis rotation does not mean the lead leg swings open like a gate. Early opening often signals the rear hip didn’t truly carry the move and sequencing is breaking down.
How can I apply this in my daily throwing program?
Use flat-ground throws to rehearse the sequence:
rear foot alignment + pressure
pelvis turning on time (Gateway)
arm rotating up earlier
on-time at foot strike
Smoothness trending closer to 1.00 as intensity rises
