MIAA Rules require that a player be U-19 eligible during the academic year they are playing. This implies that a 2x holdback will not be able to participate in school sports his senior year. Are there really examples of Kindergarten red-shirts who also reclassify in 8th grade? These players would not be U-15 eligible during their 2nd 8th grade year.

I assume most athletic assocations have similar age rules. Perhaps players do not care if they play for their HS as a senior???
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2. Age Limitations
A student who has attained his/her 19th birthday before August 31 of a given academic year is not eligible to participate.

A student who has attained his/her 19th birthday on or after August 31st of a given academic year may participate only on the Varsity level.

I am not sure I like the reclassify term. I think of it as taking a Middle School Post Grad year before starting HS.