Starting this little gambit is much easier in the early game than later on, and is normally best done after transitioning to a new size level of game, starting with medium.
When you have a whole bunch of new game-making capacity (New employees, shiny new engine, trained employees etc) Start a brand new game with a BAD combo. Make that Pirate + RPG or that Military + Adventure. Go ahead, do it! If you’ve overloaded your game making capacity and turned on all your new engine features, you’ll more than overcome the massive penalty for a bad combo game and produce a 9.0+ hit.
Next, make a new game for a strange combo. Strange combos are combos that still get a penalty (0.8) but not as harsh as bad combos (0.6). Space + Adventure would be a strange combo. Because you are making the exact same game with same engine, same genre, same employees and same engine parts… but the penalty is .8 instead of .6, your game quality will increase exactly the amount you need to get another 9.0+ hit.
An alternative to the strange combo game is to pick a great combo but a genre your team isn’t good at. If your team is focused on design, try to make a great combo action game. The unbalance of bubble ratio will simulate the same penalty that picking a strange combo would.
The third game in your series should be a normal ‘great combo’ game like you are used to making, in a genre that your team is good at. You will receive no bonus or penalty from the combo (1.0) making this game 20% cooler than your previous game. This will result in another 9.0+ hit.
The fourth game either requires you to have sequels researched, or requires an active trend that you can hit. Either (but not both) will work, as they will give you a 1.2 bonus to your game’s final quality over your previous game. 20% better, another 9.0+ hit. If you do a sequel, make sure it is a proper sequel (40+ weeks from the original and with a newer game engine). If you are chasing a trend, make sure you have enough time to finish the game before the trend poofs.
You can stretch this string to a 5th game with some luck by making a sequel that also happens to hit a trend. The two bonuses will combine to give you a massive 1.4 bonus…which is 20% better than your previous 1.2 game…and thus make another 9.0+ hit.
The downside to all this is that…repeating the cycle from scratch with a new engine is going to be tough. You are going to have to do a LOT of employee hiring, training, engine improving and such in order to have a new bad combo game beat your old 1.2/1.4 bonused 9.0 game by 20%. Try for it anyway. If you fall short, you’ll know how far up the list you have to start to get more 9.0 hits, or how much more hiring/training you need to do.