I don't know why OP need to sell tips for win on gambling. I don't know if there is any conformed way to win. If there is, then perhaps people's will be millionaires shortly. And all the shortcut way have a bad action. OP should be a millionaire since you are going to sell win tips. I am not saying you are scammer but its highly suspicious to me. So everyone should be careful about it.
Well, I do know why, even if he really has a winning method, you still can't bet absurd amounts of money, even with a 75% win rate you will not become a billionaire just by betting on sports, this is just another way of getting more money, why wouldn't you do it? I would if I had a method. Of course OP might be a scammer, who knows, can't really say, his evidence is a bit shaky though.
So in the end, this was a scam huh? I see OP hasn't posted anything else, his spreadsheet ''evidence/proof'' was definitely super shady. As I said, you gotta be careful with people giving tips, if they really have a winning strategy they wouldn't give it up that easily, you would have to pay a lot of money, otherwise why would he even sell it for pennies when he can just re-invest his own money into it?