Ex-academic, current tech monkey by day & speedrunner by night
There's a trick in Super Mario World that allows you to always get every 1up from the small bonus rooms with 3 ? blocks in a row. All you have to do is swing Mario's cape into the left side of each block, and it will always result in a green circle.
It's not just a game of chance any more!
Why on earth would that affect the random result of these blocks? Time to dig into the code.
I've wanted a technical explanation for this for ages
really lovely breakdown and fascinating exploit!! i always wondered how this room worked in general and this is soooooooo cool 
Aha, good to know my secret method of getting all five 1ups from this room now has hard data to back it up!
I have learned a thing!
I knew of the cape trick, but I also knew that it would sometimes fail. My assumption was that it failed when you accidentally hit the bottom of the block with your cape instead of the left side--that "hitting the left side" was the secret, not "hitting it with the correct part of your cape".
Video game code: wild stuff.
For similar reasons, you can also cape-thwack a shell into the block from below to guarantee a circle
I just saw a video of that being done with a Goomba!
Another video's description claimed it works if you hit the blocks when the question marks are in the center, but that didn't seem well demonstrated by the video itself. It might be an indicator of the frame counter, but it would still take some serious precision, the way I imagine it.
Oh cool! I knew this trick back in the 90s when my cousins taught it to me on their SNES. How they learned it, I never knew. But I think we all assumed it was a deliberate secret. This makes more sense though!
So that's what's up with that! I'd heard of the trick but nobody ever had an explanation for it before.
