Your position rather explicitly devolved to : something with a probability of 50.1% will probably happen, whereas the same thing with a probability of 49.9% probably won't happen.
That's the problem with folks like you who get in way over their head - you make up stuff about what actually transpired. This is a flat out lie.
My position is and always has been; anything over 50 % describes an event that is more likely to happen than not happen. Anything under 50% describes an event that has a greater likelihood of not happening than happening.
No one but you, and apparently OmSig David, on whose figures pulled out of a hat you based your argument (you never cited anyone else) would suggest that.
Re: Om, I noted, a bit sarcastically, that for once he actually got something right about language. I'm honest in that way, whereas extremely partisan folks like you find it highly disconcerting to support "opponents" even when it comes to the truth.
On the rest, another lie from you, MJ. Really, if you can't keep the arguments straight, if you can't even remember what was offered, you shouldn't be in these discussions at all.
THIS IS WHAT I PREVIOUSLY CITED.
From The Cambridge Grammar of the English Language [CGEL];
There is a third category on the scale of strength which we call medium modality, though intuitively it is closer to the strong end than to the weak.
This immediate intuitive sense is likely what first caused InfraBlue to state that 'probably/likely/should' occupied only the higher range - I don't recall exactly what he offered, let's suggest, 80-90%.
This "intuitive sense" seems to also be the reason for your stubborn, and completely unrealistic notion that 'probably/likely/should' don't also cover the low range above 50%.
This despite the meaning for 'probable' as something that has a greater chance of happening than not happening.
The CGEL clearly recognizes that the range for 'probably/likely/should' extends far beyond that high range. I'll suggest that that higher range is more accurately described by adding an intensifier, so we get,
most probably//very or highly likely
which, again, tells us that they also describe a lower range.
In speech, this lower range is often voiced by drawing out portions of the sentence,
Thhhhhatt proooooobably won't happen.
Shhhheeee liiiiikely won't be coming.
Heeeee shoooooould have known.
That these examples exist, something which no one in their right mind would deny, perfectly describes that 'probably/likely/should' occupy a much wider range than you mistakenly believe, Jack.
The above examples are definitely weaker in modal strength than these identical in meaning ones below.
That probably won't happen.
She likely won't be coming.
He should have known.
And these are even stronger
That very probably won't happen.
She very likely won't be coming.
Another of your lies, maybe just a lie of omission, is that you consistently fail to recognize and acknowledge that I devised this scale as a teaching tool to give ESLs a chance to begin to use what, for many, is the hardest part of English, the modal/semi-modal verbs.
It provides a framework where students can be easily prompted to give descriptions for situations where the instructor designates, as a check on comprehension, the student's level of certainty by means of a sign - 60%; 10%; 95%; 40%, indicating their imagined level of modal certainty.