When is the last time this happened?
Because it's borderline exploitation or even "pimping". Not just tennis, but gymnastics, swimming, figure skating, etc. have all implemented restrictions for teen prodigies so they don't go pro at 13, peak at 15, and are completely wasted and burnt out by 18, and succumb to drugs or worse while their handlers make off with the spoils. Hell, Capriati even did that, but she cleaned herself up later and had a much better and more stable second career.When the WTA initiated all of these age restrictions it did impact the development of many young players. I am not saying they did not have valid reasons for doing so, there were injuries and some young players (i.e. Capriati) had personal issues that may have been prompted by the "too much, too soon" scenario. Other juniorst might have progressed more quickly in their careers had they not been limited by the number of tournaments they could enter.