The max is 24, and when they overstepped that with 48 strokes once, the recipient had to be hospitalized. I don’t know how it’s so harmful, but it is.

https://en.m.wikipedia.org/wiki/Caning_in_Singapore

Minor? Canning is hardcore, it basically aimed at the exact spot in full strength and it will split open your ass cheek horizontally that even a masochist will yell stop. It’s a severe punishment for severe crime, one level lower than death sentence, where after each session you wouldn’t be able to walk and sit for weeks.

20 strokes will likely split into somewhere between 5 or 6 sessions over the year of imprisonment

To my understanding, 24 is the max. Caning is pretty devastating to the body. If your intent is not to execute, you have to have some restraint.

You’ve never been caned in Singapore, I gather?

I wouldn’t quite say that, no: https://www.dw.com/en/the-invisible-scars-left-by-strikes-of-the-cane/a-18298970