My notification is quite primitive. Basically I study early goals, goals scored before 8th minute. I have made a few simple tables to research how many goals are scored the first half, how much 38+ and how much in the second half. Obviously you need a lot of research and the number of games is not good enough. But so far few conclusions can be made:
Basically in only 17 out of 150 games, there were no goals scored in the first half. That is quite remarkable.
There is around 30% of the hit rate of goals in the 38-45minute mark of the first half, where odds are depending on the goal line 4-6, so obvious value there as well.
2nd half after 80th minute there is only 30% of the games without a goal. Again here we have always odds 2 or higher.
Few things to consider. There are obviously certain leagues where this tendency works better and where it works worse. The question here is the selection and monitoring the matches live, what are the dynamic, red cards, momentum, shots, etc, underdog ahead vs favorite.
Also to consider any additional notifications that can apply certain extra rules and give you alerts. Saturday, Sunday you get so many early goals that you need notification within a notification.