I also look at the referee’s history (which is crazy though).
Really crazy I would say! Maybe not to you but, this is one aspect to statistics that I’ve never had to consider. At the very least, we expect the referees to be fair in their officiating and in the event that they are not or makes too many mistakes, FIFA would be up their a$$ before they know it so, what’s their to check really with the officials to make a huge difference.
My gambling has always been about statistics and lately, I try to avoid the straight win market as much as I can, it haven’t brought me much luck in recent times and games that are that promising on wins often comes with odds that might seem ridiculous.
As much as possible, consider all angles before making a bet, especially if you are staking significant amount of money. Not only the history of the referee but the athletes, coaches involved will give you a better perspective on what to expect for the game.
It will surely take a long list before you can bet a single line. That is, if you are staking quite good amount of money. Because I don't think you will just spare a good amount of money without thinking of your bet. It may be true for most small bets but for high stakes, you would want to see that you cover all angles before you place that big bet.