25/50hz IS pal. 29.97/29.976/24hz is ntsc. So if you've seen 50hz, you've seen pal
That is actually untrue.
"PAL" and "NTSC" are often incorrectly misused as synonyms for 25/50fps vs. 30/60fps. Also 24Hz is not NTSC. Not even a little bit.
PAL simply describes the analogue (!) transmission of the colour coding (Phase Alternate Line).
PAL doesn't even define a frame rate at all (while NTSC does) - there is also a standard called PAL-60, which comes into play when watching NTSC content on PAL displays (NTSC framerate, but the signal gets converted to PAL). PAL-M is a similar thing.
It gets even sillier, when we're talking about digital content delivered to digital displays (what we're doing all the time, unless some of us are still keeping their CRT warmed up).
The acronyms in their original sense don't even apply any more. PAL or NTSC doesn't come into play at all.
But they are still used to describe the, very specific, formats 480p/i and 576p/i.
But that is mainly because: a US DVD player will generate an NTSC signal at its analogue outputs when processing 480i video.
A European player will generate PAL for 576i video and PAL-60 for 480i.
And there is no counterpart for PAL like some sort of "NTSC-50". It doesn't exist, is not defined, nobody ever asked for it.
This is why players in the US don't play back anything that doesn't easily convert into an NTSC signal (except for 24fps, which is converted to NTSC using 3:2 pulldown).
European players simply need to be able to convert US content to PAL, US players usually don't, because there's hardly any demand for this.
For players without analogue outputs (like recent UHD players, I suppose BD players as well) it should make no difference, I'd expect those to handle 24/25/30/50/60 fps all the same.
I don't know that, though.
Hope, that cleared it up a bit.