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Ichiro himself went through this. He was constantly adjusting his swing until he found the perfect swing in the middle of 2004. After reviewing the video he realized that this was the same swing he had in grade school.
Bio-analysis of the swing revealed that swing gave Ichiro more reaction time and his head movement was significantly less than even elite batters such as Barry Bonds and ARod.
Ichiro hit well over .400 for the rest of year after the adjustment and has strangely abandoned it ever since.