It couldn't happen now IMO, but it happened every now and then back in the day - which I know because it happened to me. I walked on at a top 25 D1 program and made the team. I was not recruited at that school, but I was at 4 or 5 other schools that weren't as prominent. I had offers - just not any that I wanted. The HC didn't know I was enrolled in school but when I showed up he knew who I was. There were over 200 at the tryout and 2 of us made it - both RHPs that threw over 90 mph back when not that many did. So we really stood out. I eventually earned a scholarship but it was uphill sledding all 3 years that I played there. Even though I was the hardest thrower on a really good pitching staff I never got as much opportunity as guys that were recruited. Going in I had made the decision that I wanted to go to this school regardless of baseball so I was willing to roll the dice and take what I got. The experience went a long way toward developing perseverance. which has served me well later in life.