Relief Pitcher Value Estimator: FIP, xFIP, and Save Opportunity Conversion
Evaluate a relief pitcher's true performance using Fielding Independent Pitching (FIP), Expected FIP (xFIP), and Save Opportunity Conversion Rate. These metrics strip out defense and luck to reveal a pitcher's actual skill level.
Pitching Basics
FIP Components
xFIP Components
Save Opportunities
Formulas Used
ERA: ERA = (ER / IP) × 9
FIP (Fielding Independent Pitching):
FIP = ((13 × HR) + (3 × (BB + HBP)) − (2 × K)) / IP + cFIP
where cFIP is the league FIP constant (typically ~3.10, adjusted annually to align FIP with ERA scale).
xFIP (Expected FIP):
xFIP = ((13 × (FB × lgHR/FB%)) + (3 × (BB + HBP)) − (2 × K)) / IP + cFIP
Replaces actual HR with expected HR based on the pitcher's fly ball rate and the league-average HR/FB rate (~10–11%).
Save Conversion Rate: SV% = (SV / SVO) × 100
Blown Save Rate: BS% = (BS / SVO) × 100
K/9: (K / IP) × 9 | BB/9: (BB / IP) × 9 | HR/9: (HR / IP) × 9
K/BB Ratio: K / BB
Note: IP is converted from baseball notation (e.g. 65.1 = 65⅓ innings) to decimal form for calculations.