Yep I know. Trouble is people use this to explain their chances of winning the lottery too. Which sounds about as likely since we don't have any known case of AGB patching failing?
I mean yeah, its safer to treat it as experimental at first, but saying 50% makes it sound much scarier than the reality. I assumed it was some very rough estimate based on tester reports, but it seems not to be.
I don't have any known case of this particular patch failing.
Also, this is just the "initial hook" patch (invisible, and NOT toggle-able manually). If I can't install this patch then you can't have anything else other than code-only patches (stuff like basic scale matrix alteration, section1 of the CPad patches (which disables CPad if there is not a section2 installed by the initial hook), and other generic TwlBg patches).
It might be possible though that AgbBg will always be patchable because to my knowledge it hasn't been updated in ages.