affiliationStartYearWithSeattleMariners

Given a predicate that represents a relationship or action between entities, generate a one-sentence description explaining its meaning.  
# Instructions
Focus on describing the relationship, not the entities themselves. 
# Response Format
Begin the description with \' Indicates...\'

Predicate: affiliationStartYearWithSeattleMariners

Indicates the calendar year in which an entity began its affiliation or formal association with the Seattle Mariners.