Prerequisites
- - Comfort reading box score and Statcast fields.
- - Basic arithmetic with decimals and fractions.
- - Understanding that labels change numeric interpretation.
Why This Matters
Baseball analysis breaks down when numbers are treated as bare values without context. One column may be innings, another outs, another feet of lead distance, and another miles per hour of pitch velocity. A model can still run when those units are mixed incorrectly, but the recommendation can be wrong enough to change who starts, who rests, or who gets sent down. Variables are how we give each baseball quantity a clear role before solving anything. Units are how we keep those roles honest through every operation. Teams that manage these basics well produce cleaner reports, faster debugging, and better communication across coaches, analysts, and player development staff.
Lesson Opener
In a pregame meeting, a pitching coach might ask: if our starter averages about 16 pitches per inning, how many pitches should we expect through six innings? That question already uses variable relationships, even before symbols appear. If we define ppi as pitches per inning and i as innings, then total pitches is ppi times i. The same style appears in Statcast conversations, where analysts combine exit velocity, launch angle, and sprint speed from different systems. If units are not tracked, it is easy to blend incompatible values and report nonsense that still looks polished in a chart. This lesson treats symbols as baseball labels with responsibilities, not abstract letters. We will define quantities clearly, carry units through operations, and write expressions that stay meaningful under pressure.
Learning Objectives
- - Define variables with explicit baseball meaning and units.
- - Distinguish valid and invalid unit operations.
- - Translate plain-language baseball scenarios into expressions.
Roadmap
- Identify baseball quantities and map them to variables.
- Attach units to each symbol before operating.
- Build expressions from practical baseball questions.
- Validate meaning through unit compatibility checks.