What is CRA? Definition, Formula, and Example
CRA (Core Run Average) is a predictive pitching metric that estimates a pitcher's true run allowance per nine innings by combining strikeouts, walks, hit-by-pitches, and home runs allowed.
What is CRA?
CRA (Core Run Average) is a predictive pitching metric that estimates a pitcher's true run allowance per nine innings by focusing strictly on the outcomes a pitcher controls: strikeouts, walks, hit-by-pitches, and home runs. It strips away the noise of team defense, park factors, and luck to answer a simple question: if this pitcher had neutral defense and average luck, how many runs would he give up per nine innings? It serves as an alternative to ERA and FIP by using empirically derived linear weights rather than assuming a constant multiplier for home runs.
How CRA is Calculated / Measured
CRA is calculated using linear weights values for the four "core" outcomes of an at-bat. The formula is:
CRA = [(0.445 × BB) + (0.445 × HBP) + (1.294 × HR) - (0.266 × K)] / IP × 9
Unlike FIP, which forces a league-average ERA constant to match the run environment, CRA does not add a scaling factor. The coefficients are derived from historical run expectancy data. Walks and hit-by-pitches are weighted equally, home runs carry a massive penalty, and strikeouts provide a negative value (meaning they subtract runs from the numerator, lowering the pitcher's CRA).
Worked Example
Let's calculate the CRA for a pitcher with the following seasonal line: 180 innings pitched, 45 walks, 12 hit-by-pitches, 22 home runs, and 210 strikeouts.
1. Walks contribution: 0.445 × 45 = 20.025
2. HBP contribution: 0.445 × 12 = 5.34
3. Home run contribution: 1.294 × 22 = 28.468
4. Strikeout subtraction: 0.266 × 210 = 55.86
Add the positive weights and subtract the strikeouts: 20.025 + 5.34 + 28.468 - 55.86 = -2.027.
Divide by innings pitched: -2.027 / 180 = -0.01126.
Multiply by 9: -0.10 CRA.
In this specific example, the pitcher's strikeout total is so high that it entirely offsets the damage of his walks and home runs, resulting in a sub-zero CRA. This indicates an elite ability to prevent runs independently. A more typical MLB starter sits around 3.50 to 4.20.
Why CRA Matters
CRA matters because it provides a more stable and accurate projection of future ERA than traditional ERA itself. Because it removes defense and luck from the equation, front offices use CRA to identify pitchers who are overperforming or underperforming their true skill level. If a pitcher has a 2.50 ERA but a 4.50 CRA, regression is imminent. Fantasy baseball players and DFS sharps use CRA to find buy-low or sell-high candidates before the broader market catches on.
Limitations and Common Misconceptions
CRA does not account for the quality of contact allowed (like exit velocity or launch angle), which is why modern metrics like xFIP or SIERA are sometimes preferred alongside it. A pitcher who gives up weak contact but avoids home runs might have a worse CRA than his actual run prevention suggests, because CRA treats all non-home-run balls in play as identical. It is also often confused with FIP; while both focus on the same three outcomes, CRA uses dynamic linear weights and no league-average scaling factor, making it mathematically distinct.
Related Terms
In Legends Deck: We use CRA-adjacent core metrics to power our pitcher card ratings. A pitcher's raw Stuff grade on Legends Deck is heavily influenced by their strikeout-to-walk core ratios, ensuring that in-game simulation results reflect true, defense-independent talent rather than real-world luck or team-dependent ERA.