Background: I never came close to playing D1 college baseball or anything but played varsity in high school and everything and could hold my own. My argument as to why I would get a hit rests on three things....
1. I wouldn't be looking to draw a walk. This is important because it gives me an extra hundred or so chances at a hit that most major leaguers don't get. I have a 3-0 count? I'm looking to hack.
2. I'm not facing Clayton Kershaw 600 times. Do people realize how many AAA bums make appearances throughout an MLB season? I realize my hit isn't going to come off Kershaw, Bumgarner, or Chapman but if some scrub hangs a curveball I'm pretty sure I could bloop it into right field.
3. I would get so much better as the season went on. This is my argument's best point. My hit isn't coming in the first 100 at bats. Those are just to get my timing down. Honestly it's probably not coming in the next 100 either. But after months of working with MLB hitting coaches my swing would improve dramatically plus I would have hundreds of at bats to get my timing down. Come July I could be facing a checked out reliever on the Phillies in a meaningless game.
Now there would be other factors as well. The media attention during the first 100 at bats would be excruciating. No pitcher would want to be known as the guy who gave up a hit to me. I will have to be 0-250 so the pitchers let their guard down a little. I'm also not even sure my teammates would like me. MLB players don't want some recent college graduate hanging around who has never even played college baseball.
I would also have to adjust to the lifestyle. As an MLB player I would be making league minimum which is a little over $400,000 so you know I wouldn't be getting the right amount of sleep most nights. After a while though I will be ready to commit to my craft and will stop partying (or I'll just run out of money). Basically that means the only thing that could slow me down would be injury and if it came to that I would just pop some HGH, Peyton Manning style.