You can not compare the US Amateur boxing system with the European one. In Europe you have a lot of club boxing so you have several fights in a month. If you participate in these leagues and competitions you have like 40-50 fights per year. I think the US system is much, much better because it's more friendly for the athletes. Boxing in Europe on the amateur level is brutal and sometimes these guys are already done before even reaching the pro ranks. There is also the tendency that Europeans leaving the Amateur ranks later. There are a lot of Europens who are still amateurs in their late 20s while in the US it's more common to turn pro early in the 20s because boxing is a much bigger sports over there. I don't think there is a right answer for the question how many amateur fights you should have before turning pro. It depends on a lot of things. My feeling tells me 50-100 is a good number if you have the skills and physical attributes to turn pro.