look for Paulo Rebelo, Psychoff.... on football trading resources, I bought some just to get a look into what they supposedly do, Total football trading I think and a service called goalprofits... About GP, they use stats, dont watch games, maybe you will like it, its all about your trading psychology/profile.
I think there are so many ways to make money inplay, lately I have been looking into the Asian Handicaps, asking for prices at betfair that I think have a lot of value. You can base this assumptions on stats or just by looking into a game, with time and some record keeping you will find patterns worth investigating.
I think that you have to look into something that not only gives you money, but that you enjoy. For instance, if you look into La Liga (spain) stats for this season, you will find some odd things happening. Teams with possession are losing. Few goals. Two years ago I made money mostly in the first half of the game, with big possession teams pressing, because I liked to play like this. I avoided second halfs. I calculated my edge and it was not something spectacular, my discpline started to diminish and some losing runs made me change my strategy into something more attractive. I used no prematch stats. If I sticked into this games without looking into other things, I would be suffering right now, since I also used a very aggressive stake % of my bank.
After a year of getting good results with first half, big possession teams, I started making money in the second half. I started to look into some prematch data and tried to make a system, something so easy any one could do it. I think anyone that follows those instructions will make a decent return but then again, I wanted to be better so I started to look into other stages of the game and new markets.
I used to be very very bad at over/under markets, I took a dive into all the games I traded and found patterns that are very promising into the late stages of the game.
Now I profile matches using basic stats prematch, I combine this data with the current inplay situation and start trading what I see. You can paper trade, but I dont like this, because theres no point into finding value at odds like 10, 15, 30 if you cant stand a losing run of 15 games, even if you come out on top after a hundred bets, so I bet to know how much of a beating I can take. After a few games, 20, 30 maybe, you will find promising things, continue and you will get something. Then, its all about discipline and finding other angles. What I am trying to tell you is that you have to continue working on different angles, trying to get a very big edge, I am talking about winning 30% on odds of 5, which is about a 50% edge on your stake. I dont think I can get those on a prematch bet.
Take a look into any Big Team game, you will see their odds fluctuating depending on how they are playing and how much time they have left, I can assure you that a team like PSG can win games from a goal behind in 10 minutes, you just need to look into when they want to do it and if the odds are good enough for you. Thats it.
Look for "sure things" in the mind of your average bettor, almost all the time they will suffer their bet, it does not matter if the odds were 1.3 or 1.7..... Just take a look into how some big teams do not even try in the first half, or some mediocre teams get so motivated into the first half they come out attacking and making the goal. Just think, explore different ideas and you will get something interesting.
Read the market wizards books.... you will see that you can make money with or without stats, just look for something that suits your personality.