The truth is players are missed every year. The scouting community has two things that determine success.
1. Present ability - this is somewhat easy and if they see it, they know it.
2. Projection - how good will this player be 4 or 5 years down the road. This is the tough part and is often missed badly. It requires a prediction based on many things. The more you see a player the more likely you will make an accurate prediction. Often these type players are not seen enough to make a good prediction. Often they end up at small colleges or even out of the game.
A good example pitched in the All Star game last night. A tall skinny lefty who threw low to mid 80s most often in hgh school. He went to a small DI only because he was seen in their hometown at a showcase. No big scholarship, but got his chance to further develop. Chris Sale!
another example... Chris Lambert was a legion player in the NE. He was an excellent athlete and a hockey player. He also had a mid 90s fastball that was unfounded by the scouting community. He had finished his senior year in high school without a single baseball offer. He was going to play college hockey. In August after his senior year he showed up at a showcase in Wareham, Mass. He then became one of the most sought after prospects in the country. LSU, Clemson, North Carolina all went after him and he committed to Boston College his dream school. He quickly became a first team freshman All American and was drafted in the first round after his junior year. The entire scouting world missed him until that showcase after his senior year. The story is probably still out there on google.
I could give many examples. It only requires a little common sense to believe thereare people out there who never got that last chance with scouts and recruiters. There are many who just didn't get seen enough or at the right time. There is no way to prove this, but I truly believe there are people out there that could have become Major League All Stars had they just been found.
All that said, I do believe the scouting community does a great job. They actually do find "most" of those with unusual ability. They also find some of that talent late in the process every year. And some they don't find in time.
So for anyone to say, If you're good enough they will find you, it's not totally accurate. Without Tommy Lasorda's connection, they would have missed Mike Piazza. Not everyone has those kind of connections. Nearly every player drafted each year is someone we have a file on. I'm absolutely positive that we miss several players every year. I don't know how to say it any other way, we see more players than any organization in baseball. And we still miss a lot of them! A lot of them are missed by everyone, every year. They get missed in most every state including California, Florida, and Texas, let alone other states. Sometimes they are missed despite being seen. It's impossible to find them all.