What an awesome game! This is one of my favorite machines from any era. Its just amazing especially for the era. The ruleset of this game is so far above its contemporaries, its in a class of its own! The ball lock at the top adds so much to this game imo. Basically it creates a sequence of objectives that you need to complete in order to maximize your scoring, which adds strategy and risk.
My ideal strategy currently is to complete the right bank and lock the ball in the top. Then complete the left and right banks as many times as possible to get the bonus as high as possible. Once you have the the super bonus x maxed out it will not reset like regular bonus x after a drain so it wont be necessary to complete the right bank anymore. Assuming I still have a ball locked in the top, I like to get the right bank primed but leaving the last two targets up in case I drain as an insurance policy so I can open that upper lock and get the ball back up there.
At this point hopefully I've got 25x bonus and phase two begins, rip the spinner! Basically when the ball is in the top lanes you want to make sure you light the bonus collect at least once before you drain so the next time you shoot that top lock hopefully you have maxed out your bonus score and get a huge 25x collect. If the bonus collect is already lit get as many extra ball advances as you can while you are building bonus. Rinse and repeat.
So of course you will drain eventually and that will screw up your happy top lock situation but completing that left bank for bonus x also lights the top left saucer for a lock. There is no reason to shoot this lock when you have a ball locked at the top and in fact you want to avoid this lock as much as possible. However building bonus requires the ball to go to the top lanes and every time its up there an unlucky pop bumper hit can ruin your top lock and put you into 3 ball multiball. If you have your right bank primed down to 2 and one of these balls knocks the targets down during multiball you are screwed because the completion won't open the top lock again. It can only be opened in single ball play so now you have to get the entire bank completed before you can lock up the top again. So its actually better in some cases to drain the other two balls if multiball starts. In a situation where you've got the right bank primed but the left lock saucer is lit, you might actually want to collect that for 2 ball multiball so you won't run into a situation where your happy top lock situation can be later ruined.
When you are playing against other players the strategy that comes into play is how far do you want to take this bonus x advance thing before you start building up bonus score and going for collects. Its so much more than shoot targets for score or start multiball and hope it lasts a long time and racks up good points like so many other games of this era.
Chess and Checkers might be played on the same board but thats where similarities end. If you can think of another 80s Williams that involves as much strategy as Barracora let me know! 10/10