Michael Ray Jackson is a former professional baseball player whose career spanned 19 seasons, 17 of which were spent in Major League Baseball (MLB). Jackson, a relief pitcher for the majority of his career, compiled a career earned run average (ERA) of 3.42, allowing 451 earned runs off of 983 hits, 127 home runs, and 464 walks while recording 1,006 strikeouts over 1,005 games pitched.

A hold is awarded to a relief pitcher who meets the following three conditions:Enters the game in a save situation; that is, when all of the following three conditions apply: He appears in relief when his team is leading; and He is not the winning pitcher; and He qualifies under one of the following conditions: He enters the game with a lead of no more than three runs and maintains that lead for at least one inning He enters the game with the potential tying run either on base, or at bat, or on deck He pitches for at least three innings; Records at least one out; Leaves the game before it has ended without his team having relinquished the lead at any point and does not record a save.