Let me preface this by saying, I know some people will hate this, and that's fine. You don't need to do it or download it. For everyone else that is pulling their hair out trying to get the Perfect Game or No-Hitter trophies, then this is for them.
I've been working on all the RTTS trophies first, and this isn't even a mode I particularly like. The last trophy I needed was the Perfect Game, and I was going nuts. I even waited to the Majors before really going for it, because I figured I'd need the higher stats anyways. Game after game, and I couldn't even get close. I even tweaked all the sliders to make it easier, and still nothing. Then I had an idea.
I had chosen the Dodgers to draft me, but I was then traded to the Royals, so I figured the Royals must need pitching. What I did was edit all the fielders on the Royals AA team. Every position player now has 99 fielding and speed. I then picked a team that the Royals AA affiliate plays a lot, Arkansas (Angels affiliate). For that team, I set every position player's stats to 0 for hitting and speed. I didn't change any other team, just ARK. In addition to changing stats, I also moved all relevant sliders to give me an advantage, both in the field and pitching against the CPU.
It took me a few weeks to make the starting rotation. By the second go around against ARK, I was in the rotation, and my results were awesome. First try a 1-hitter, and second game I was perfect. It's actually quite funny to see the ball come off their bats. It's like their bats are made of foam.
Make sure you set the difficulty to All-Star or you won't get the trophies, and you can also use all the aids you want. I checked the cold/hot zones before each batter, and hammered away at those. I'd also recommend you put all the training points possible into stamina, and your fastball. This will also earn you the no-hitter trophy at the same time.
You can find it in the roster vault as a fantasy roster:
Easy Perfect Game RTTS
Good luck!