Hitters usually have a fairly linear development path. Pitchers may invent a new pitch or adjust their mechanics and in the process transform themselves from year to year, but hitters progress more steadily, evolving by steady degrees. Once a hitter has established himself as a regular in the major leagues, it is unusual to see him suddenly regress to the point that, after a period of years and/or a substantial number of games, he has to be sent back to the minor leagues for re-education.
19hMike Vorkunov for REDEF
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