Forget about gambling but when it has to do with speculations, I don’t believe in them until when proven certain. This is money we are talking about and you’re believing some speculator that can just speculate anything out in order to get recognised for their work. If it goes well for them, they’ll get more people to join them and when it goes against them, they try to buy you through another means to believe them the next time again. No one is guaranteed to be perfect in what they do, there’s always some discrepancies in everything you do and that’s natural for a human being.
Even so called Professional or experts in betting or gambling cannot get 100% of accuracy, if they do they would be likely cheating the system somehow, which is obviously illegal and against the Terms of Service of any casino out there. The whole point of being an expert at predictions is by being able to correctly call the results of matches more occasions than those incorrectly called, if done in the long term when it becomes profitable for the person and people who also bet using their tips. Whatever it bigger than 50% of accuracy, it is translated to profits in the long term.
Though, as I have already said in the past. One should have no reason to believe someone with the skills to get profits out of betting with those rates is willingly giving their tips, neither for free for changing for them, because if it was about money, they could just bet with their own money and get what they need. I only would pay attention to free tips, and from someone who despiste of having a good track record, does not give Tips all the time. It should reasonable to take tips in that context.