ERA - a Model System Structure

ReadBaseball statistics are the best numbers in the whole world. They measure performance in constant terms that delineate the play of a game in a form that allows direct comparison of eras. Eras are periods of time that only appear in retrospect. You are never part of an era when you are living and doing, only when you glance back to see how time has passed, do you recognize your role in history.
ThisERAs are reflective of how often the pitching goal is met - a 3.00 earned run average should be in the running for the season title. In a 9-inning game, that translates to success two thirds of the time. Since a .333 batting average is also darned good - the mathematics of the sport have an internal consistency second to none.
NowSo why do we allow the education system to put additional pressure upon all youth via the disservice of attempting to achieve 90% (or higher) for an 'A ' grade - when the whole process is unrealistic and just defeats psyche and willingness to contribute productively in very short order? Let's make our averages reflective of baseball averages and make kids feel good about hitting home runs, instead of being held to an unreasonable standard of inconsistant perfection!!