Building A Player Development System for Your Program

This article by Adam Schuck covers the simplest way you can begin systematically getting your players better by using the Test/Retest Model.

What’s up guys! I’m pumped to be a part of the new Simple Sabermetrics Blog. Most of my contributions to this community will be pitching oriented, specifically focusing on tech commonly used in today’s game, basic analytics (Simple Sabermetrics if you will), and different player development methods.

So, who’s this new Adam Schuck guy anyways?! Jake and I met working together as student managers at the University of Iowa starting back in 2016. We’ve spent our fair share of time together doing everything from catching bullpens and cleaning equipment, to assisting our coaching staff in player education. I’m currently still a student manager at the University of Iowa and a MiLB Tech Coordinator for the Baltimore Orioles.

My passion for player development was born from being nothing more than an average high school catcher and not really knowing what to do about it. As embarrassing as it is to say, I was one of those kids that would spend all night googling things like “Catcher Specific Hitting Program” and “What Muscles Matter For Catchers” to try to find the optimal way for me to succeed. I would try pretty much anything and everything on a whim. If I didn’t see immediate results it was out and I was on to the next thing. I simply just didn’t know any better.

Upon coming to Iowa I was very fortunate to have a coaching staff willing to talk shop any time, and boy did I have a lot of questions. Throughout that first year being around our pitching staff daily and constantly asking questions, I really began to embrace the idea that although my playing career was over, I had the opportunity to help other players get closer to their goals which was just as rewarding, if not more.

Quickly, I learned just how wrong I was while looking for very specific quick-fixes for my own development as an athlete and how it would have been much more effective to just create a plan to develop within. Simply having a plan that every athlete goes through to systematically evaluate their performance is key to holding both you and your athletes accountable for their development. It’s my opinion that this is one of the lowest hanging fruits in player development and those who take the time to really sit down and create a well-thought out idea of what this process looks like in their program will reap the largest benefits. In the rest of today’s piece, I will be talking about what this might look like from a broad perspective.

Building Your System

An easy way to think about the player development process is through a test/retest model. First, you implement a training stimulus to improve an athlete’s specific weakness and then you retest to see if it worked. Simple enough right? I’ll expand on this a bit more and break it down into a six-step process.

1) Assess

2) Evaluate

3) Program

4) Train with Feedback

5) Reassess

6) Repeat (if Necessary)


To start off this process, we are aiming to learn

where exactly our players are currently at

with their skills, movements, decision making, etc. Preferably these are things that we are able to quantitatively (numerically) measure pertaining to the intended area of focus. In this example let’s say our goal is to determine whether an adolescent pitcher should fall into a velocity, command, or pitch design focused training schedule for the Fall semester. If you are limited on time/resources you should at least measure each athlete’s ability in each bin of interest. In this case we’d look at things like fastball velocity, overall in-zone percentage (command), and arsenal performance (pitch design) to suggest what bin they may fall in. Let’s use CSW% to measure our arsenal performance. If you want to know more about CSW, look here!

Ideally you would measure all previously mentioned variables, as well as other things that may affect them such as throwing mechanics, flexibility, strength, etc. Now, I’m not saying you need a team physician and a full-on biomechanics lab with force plates to get all this done. You can get more than enough information with some iPhone video and a strength/mobility assessment from a local Athletic Trainer focusing on joint specific and functional movement ranges.

After completing this I imagine you now have more numbers to look at than you could ever possibly comprehend at once. Don’t worry there’s a player plan in there, we will get to that in our next step. Before that, let’s put all your information in one spot. If that’s, Excel, Google Sheets, Tableau, etc. then great. Just use whatever you are the most comfortable with. It doesn’t have to be fancy, just something you are able to easily interpret and recall information from.


You’re now the data king/queen with spreadsheets of information. Awesome! Let’s use this information to identify a specific area of improvement you feel is holding your athlete back from reaching their potential. Now comes your coaching pillars and what you value in your program.

Looking at our assessment, what is it you feel is the single most important thing in the success of your athletes? This should be the first checkbox an athlete needs to hit. Since this is most valuable, you would want to make sure an athlete has this skill/ability down first before moving on to more advanced ones. If you are a “95 mph doesn’t matter if you can’t command it” coach, maybe you want to prioritize command before velocity and pitch design. If you’re the “you have to throw 95 to be able to command 95” coach, then maybe velocity is your top priority followed by pitch design and command. For this example I’m going to use velocity as our top priority.

Let’s say our athlete of interest is a 19 year-old male who has been lifting and pitching in travel ball since his freshman year. You and your local Athletic Trainer run him through an assessment and he shows an overall lack of lower body strength, no movement restrictions but an inability to properly hip hinge, he’s more flexible than most in his t-spine and shoulders, displays poor trunk positioning at foot plant, possess an average fastball velocity of 84 mph (Below Average) with a 53% (Above Average) in-zone rate, and a max of 23% (Poor) CSW rate on any pitch.

Now, let's go back to our 3 bins for evaluation: velocity, command, and pitch design. It seems he could use some work in both velocity and pitch design. Looking at the graphs below you'll notice our athlete falls far below average MLB fastball velocity, as well as being in the bottom percentile with is CSW%. His in-zone rate falls in an acceptable range above 50%. Compared to MLB athletes, this is understandable - but that's the end goal right? Since velocity is the #1 box to check off in my developmental model, that is what we are going to attack first.


Since we’ve already determined that this program will occur in the Fall semester, we aren’t under many time restrictions which helps our options. If this was 6 weeks before the season, improving velocity would probably be off the table as that’s a bit too quick of a turn around into competition. Since we have plenty of time, we’ve decided the best way for this athlete to improve is for him to increase his fastball velocity. Now what? Let’s continue to put the pieces together from our assessment through a process called Backwards Chaining. Backwards Chaining is a process popularized in the baseball world by Driveline Baseball that notices an outcome or issue and looks back at what happened before that moment to cause the outcome.

An example of this process for the athlete we are evaluating would be first identifying the lack of velocity. Why is there a lack of velocity? Possibly due to poor trunk positioning. Why is the trunk in a poor position? Possibly due to poor positioning of the pelvis. Why is the pelvis positioned poorly? Possibly due to the athlete’s inability to properly hinge/load their hips. Why is the athlete unable to properly do this? Likely due to a lack of strength. Hey! Our assessment showed a lack of lower body strength and difficulty hinging, what a coincidence.

By walking through this process backwards, we can properly identify what the root cause of the problem is and attack that rather than what we perceive the problem to be at face value. Rather than internally cueing an athlete to “get out front” to gain that forward trunk tilt let’s address the thing actually causing that issue to occur. By doing so, the athlete will likely improve this movement long term rather than a short term over-cued fix that may create additional problems since the root wasn’t properly addressed. In this case, it’d be appropriate to tone down this athlete’s throwing volume and focus on building a solid foundation of strength in the weight room while incorporating low and moderate intensity plyo days to reinforce desired movement patterns.

Side note: If your athlete is under 20 years old I’d be willing to bet most of their issues stem from a lack of foundational strength but that’s a conversation for another time.

Train with Feedback

Being able to receive consistent quantitative feedback on their performance may just be the most impactful information an athlete can receive regarding their personal development. Evaluating performance by “feels” can only go so far. A specific change you’re attempting may feel right, but may actually be negatively impacting your performance. Let’s say you received a baseline assessment in which you threw 88.4 mph. You’re instructed to focus on increasing scap retraction during plyos and catch play for the next 3 weeks then get back on the mound and see where your velocity is at. You spend the next three weeks feeling like you’re taking your elbow all the way to your spine and during your next assessment you top out at 86.1 mph. How frustrating would that be?

What if for most throws 3-4 times a week, you knew exactly how hard every throw was? If you maintained the same effort level and noticed a change in velocity (up or down), that gives you feedback on just how successful that “feel” you’re trying may be. Right then, you’re able to adjust on the fly rather than waiting for a training block to be over and reevaluate. It is through this logic that most training should be approached in my opinion. Whether it is getting bar speed in the weight room, exit velocity in the cage, spin efficiency during a pitch design session, etc. Consistently receiving objective feedback is crucial for an athlete to maximize their training efficiency. A study further expanding on this topic while investigating the impacts of instantaneous feedback for weightlifters can be found here.


While consistent feedback on a specific metric can be a strong developmental tool, there’s no need to do a full evaluation and repeat step 1 every week. Frequent over evaluation like this often leaves both the coaches and athletes confused with a nice head full of yip salad. It can be beneficial to track trends on a few lifts, velocity in bullpens, or slow motion video to see how they are progressing or regressing, but again there’s no need to do a full assessment every week. Tracking these trends can allow you to step in if things are continually headed in the wrong direction. Overall, mechanical and especially strength changes often take weeks or even months to occur and we need to allow an adequate amount of time to make these changes before jumping to conclusions that our program was or was not effective.

Given that the athlete in this assessment is focusing on strength-based changes, we would probably want to allow 8-9 weeks of development before completely retesting strength levels. It could be beneficial to do a brief check-in every two weeks to see how their mechanics are progressing and possibly a high-intent day at the 4 week mark to see if things are transitioning well onto the mound, but that is about it. Changes take time. If it was easy everyone would do it, right?

Repeat (if Necessary)

Here we are again, back at step 2 now. We've completed our assessment, now let’s evaluate the athlete’s current state and repeat! However, let’s not forget about the time of year we are currently in relative to the start of the season. Our athlete started an 8-9 week program at the beginning of the fall, let's say September 1st. This puts them at November 15th following a deload week - assuming everything goes to plan. This gives us 12 weeks until the first game. Allowing a minimum of 4 weeks for on-ramping, this leaves us 8 weeks to work with.

Depending on how successful our training period was at increasing velocity and cleaning up the desired mechanical changes, it could be advantageous to stretch it out a few more weeks or possibly blend to mound work early and focus on pitch design, our athlete’s #2 weakness found in our initial assessment before on-ramping for competition. No matter what you do, make sure you allow your athlete adequate time on the mound before competition.

Wrapping Up

To recap this all, it is not my belief that any one development plan, or secret formula, is the optimal way to train all your athletes. It may work for some with spotty results, but ultimately an effective way to develop all types of athletes is through something like the 6-step test/retest model we talked about today.

First, assess the athlete objectively and preferably quantifiably. Now, evaluate their assessment. What are their strengths and what are their weaknesses? Next, it’s time to program. Which one of their weaknesses is most significantly impacting their performance and how much time does the athlete have to make changes before preparing for competition? Once you’ve got that figured out it’s time to train. Make sure the athlete has objective feedback throughout the process to check if the feel they’re attempting to implement is favorable or not. Then it’s time to reassess. If a large period of time has passed, let’s completely repeat the assessment process. Otherwise, let's just look at the things we trained for and see how those progressed. Finally, time to repeat. Consider how much time you have before the athlete needs to return to competition and program accordingly.

Thanks for reading everyone! I appreciate you welcoming me into the Simple Sabermetrics family. Stay tuned for more info on tech and pitching from me soon!


Fast, Alex. “CSW Rate: An Intro to an Important New Metric.” Pitcher List, 2019,

Vanderka, Marián1; Bezák, Anton1; Longová, Katarína1; Krčmár, Matúš2; Walker, Simon3 Use of Visual Feedback During Jump-Squat Training Aids Improvement in Sport-Specific Tests in Athletes, Journal of Strength and Conditioning Research: August 2020 - Volume 34 - Issue 8 - p 2250-2257

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