Zack Greinke (former Kansas City Royals/Houston Astros) belongs to the ‘Conceptual’ motor skill group (C) in his big loop and the ‘Global’ motor skill group (G) in his small loop. This means his movement patterns and movement patterns shift depending on fatigue, stress, and learning phases.

Throughout his career, Greinke has been known for his slow, methodical style, but his movement patterns subtly adjust as he fatigues. In longer outings, he shortens his windup and keeps his arms closer to his body, a common trait of Global (G) athletes.

Understanding the Big Loop vs. Small Loop in Motor Preferences

Your brain operates using different motor profiles, which shift based on fatigue, stress, or learning. Most of the time, you function in the big loop, where your dominant motor preferences are most evident.

What is the Big Loop?

Think of the big loop as your natural motor profile—how you instinctively move and interact when you’re fresh and relaxed. For example, if my dominant profile is G4, I’ll naturally exhibit certain traits and communicate in a specific way. However, under fatigue, stress, or deep learning, I will make a transition into a different motor profile, such as C1, which alters my preferences and movement patterns.

We categorize these into:

• Structural Preference – Core motor tendencies that rarely change.
• Dynamic Preferences – Motor adjustments that happen more frequently based on the situation.

Backup Loops and Creativity in Sports

Elite athletes have backup motor loops that allow them to adapt, be creative, and execute unexpected movements. One of the most iconic goals in football history was scored by Zinédine Zidane (France) while operating in his third motor profile—something we can physically measure.

Analyzing Zack Greinke’s Mechanics: A Shift Between Loops

When Greinke is in his big loop (C-G), his mechanics exhibit:

• A methodical windup.
• Synchronization on the right side.
• Engagement of the posterior chain.
• A hinge movement between the upper and lower body slightly deviates from an ideal biomechanical model.

However, when fatigue sets in or adjustments are needed, he transitions into his small loop (G), where:

• His windup becomes shorter and more compact.
• He keeps his arms closer to his body (which is a typical Global (G) Property).
• He needs to engage his entire body, with a stronger emphasis on the large muscles of the core and legs.
• Due to a fixed relationship between the hips, elbows, and shoulders, the upper limbs play a more limited role in movement.
• He accelerates primarily from the hips.
• He relies mainly on the middle-front muscle chain for power.

Are Coaches and Players Paying Attention?

These motor shifts aren’t random—they follow predictable patterns. As a coach, player, or analyst, understanding these changes can provide deeper insight into performance fluctuations. When a player enters a different loop, it’s not just their movement patterns that change—their decision-making, communication, and even body language shift.

Are you noticing these subtle changes in your athletes? If you want to learn more about motor signatures and motor preferences, reach out and explore how this science can unlock new levels of performance.