What are some obscure or weird rules that you know that might be useful to know, but it appears that not many people know?
Here are a couple from Indy 500:
1) In regular multiball, most people know that when you put a ball in the Turbo, the regular jackpot value increases by 10 million. However, an important detail to note is that not only does the scoop switch need to register for you to get this score increase, but the upper Turbo mech itself needs to register. This means that it's possible to put a ball in the Turbo and shoot a jackpot too early, receiving only the regular jackpot value rather than jackpot+10 million. For example
(Start at 1:09:30 if the video doesn't automatically start there.)@cayle
locks a ball in the Turbo and then gets a quick 30 million jackpot via the right ramp that would have been 40 million if he had waited ~1 more second. He then shoots the left ramp and gets the expected 42 million. (Each made jackpot raises the next jackpot value by 2 million.)
Also note that if you're playing an Indy 500 where you can hear the machine's sound cues, the game will issue a beep when the value has been added to the jackpot.
2) In video mode, you don't have to avoid the oil slicks. You don't get more points to go through them, and they will slide your car if you are not providing left or right button input, but this knowledge might earn you some extra points toward the end of the mode.The rule sheet says "...if you just skim an obstacle you only skid a bit," but that's not exactly correct.
3) If you're playing with extra balls off, don't select "Light Extra Ball" from the Change Setup award. It does what you'd expect for a game of this era: nothing.
EDITED TO ADD:
4) When you launch a ball, there's a regular ball save light, but the blinking car in front of the left ramp also indicates that there's an additional hidden ball save/grace period. If you center drain with this car blinking, you will get your ball back. Any side drain that turns off this blinking car will not be coming back, but it's possible to drain out the side with the regular ball save light off and have the blinking car not turn off and have your ball saved.
Minds blown? Bored to tears? Either way, it's your turn now. Are you harboring any deep cuts you wish to share with the world?