Quoted from NoSkills:
But I actually think a button for each flipper makes it more difficult for someone who has never seen a pinball machine. A certain level of play you don’t need to stage flip, thinking about which button to press adds to difficulty. 2 buttons to flip all the flippers or 4 buttons (for a 4 flipper game), 2 buttons is easier.
Think about how many people still flip both flippers at the same time because they’re not sure which is best, especially during mbs, they’re just going to be sitting there either mashing 4 buttons or ignoring the upper flippers or loosing their finger placement switching between. It’s not just that I think it’d be worse for me, I actually think it’d be worse for new people too.
That is why I specifically said, "Assuming you want the user to be able to operate each flipper independently".
If your objective is to make the game as easy as possible for someone who has never played the game to play. For a new player, two buttons is excessive as we all know any new player instinctively just wants to trigger all the flippers at the same time.
My Summertime game which is an early flipper title is wired so that both the left and right flippers fire regardless of which button is pressed. One button for all flippers is easiest to figure out.
I personally think people are capable of figuring how to use an extra button. It would take time, just like it takes time to learn how to use two buttons separately. That is just part of getting better. Most people who play my WCS94 don't even realize there is another button for magna save. When they figure that out it just becomes another fun element to master.
It is not much different than Sterns middle button. New players don't know when to use it, they don't get that there are rules to the game, they just bash a ball around without it and have fun. As they start to figure out how to keep the ball in play for more than 2 seconds.
Don't get me wrong, I've played the P3, and thought the upper flipper being on a separate button was awkward. That being said, I fully expect if I played it more I'd begin to prefer that approach over the norm.