This page is intended to provide readers with glossary of terms commonly used on the site and in and around the baseball community.
Minor League Levels:
The Astros have seven minor league affiliates.
Triple-A – Sugar Land Space Cowboys
Double-A – Corpus Christi Hooks
High-A – Asheville Tourists
Single-A – Fayetteville Woodpeckers
Florida Complex League (FCL) – Astros
Dominican Summer League (DSL) – Astros Blue, Astros Orange
Triple-A, Double-A, High-A and Single-A are all considered full season affiliates as they play a full season of games.
FCL Astros and DSL Astros are considered rookie level affiliates and they play a limited season.
Offensive Metrics:
OPS – On base plus slugging percentage.
OPS+ – Takes a player’s OPS and normalizes it across the entire league, accounting for park factors. For OPS+, 100 is average with any number over or under representing the percentage above or below. For instance, a 120 OPS+ is 20% better than league average.
Weighted Runs Created Plus (wRC+) – This number takes the runs a hitter has created and adjust for external factors like park factors or era. As with OPS+, 100 is average and any amount over or below is the percentage higher or lower than average.
BABIP – Batting Average on Balls in Play.
Launch Angle – Vertical angle of the ball’s trajectory off the bat.
Exit Velocity – Speed of the ball off the bat.
Pitching Metrics:
ERA (Earned Run Average) – Average runs allowed per nine innings.
WHIP – Walks + Hits per Inning Pitched.
K/9 – Strikeouts per nine innings.
BB/9 – Walks per nine innings.
FIP – Fielding Independent Pitching (removes defense from ERA).
Velo – Pitch velocity.
Spin Rate – RPMs on a pitch, affecting movement.
General:
40-Man Roster – The list of players protected from the Rule 5 Draft and eligible for MLB.
Options – Years a player can be sent to the minors without being exposed to waivers.
International Signing Period (ISP) – Time when MLB clubs can sign foreign amateur players.
Ceiling – The highest potential a player could realistically reach.
Floor – The lowest reasonable outcome for a player’s career.
ETA – Estimated Time of Arrival in MLB.
MLB Draft:
Rule 4 Draft – Commonly known as the MLB Draft, this 20-round event allows teams to select eligible players from high school, college, and junior college.
Bonus Pool – The amount of money the team is allotted to sign drafted players.
Signing Bonus – In the first 10 rounds of the MLB Draft, each pick has a set bonus amount. The total of these amounts forms a team’s bonus pool.
Over Slot/Under Slot – Each MLB draft pick has an assigned slot value. Teams can go over or under that amount but must stay within their total bonus pool. Savings from underslot deals (e.g., a $4.12M slot signed for $4.0M) can offset overslot signings.
Rule 5 Draft – The Rule 5 Draft, held each winter, lets teams select eligible players from other organizations. Players signed at 18 or younger must be added to the 40-man roster within five seasons; those signed at 19 or older within four. Unprotected players meeting these criteria can be drafted by any team.
Transaction Terms:
Call-Up – When a player is promoted to MLB.
Optioned – Sent to the minors while on the 40-man roster.
Designated for Assignment (DFA) – Removed from the 40-man roster.
Released – Player’s contract is terminated.
Waivers – Process for other teams to claim a player.
Injured List (IL) – Roster designation for injured players.