If you're referring to the sheet I made, it determines my strategy every match (I don't use the fixed counter formations that are used in the other spreadsheet...still a cool idea). I've only added the tactics over the last 4 seasons with the tactics only being usable last season. So I don't have too much history the tactic effectiveness with behind the scene changes. For some reference, last season was the first season I used the tactics exclusively (I used the 3 previous seasons for experiments). I pulled off a double taking down many stronger (20+% opponents) and only lost 3 games (2 in cup quarterfinals to knock me out and 1 throwaway end of season game). My CL final win was against a 145% beast using 4-5-1v. This season, I've already lost a game to a slightly weaker ND at home 0-2 (me: 101%, opp: 100%). Struck me as weird since the day before, I faced stronger ND away and won 0-5 (opp: 108%, me: 100%). So obviously, nothing is fool proof. Note: no managers were present for my ND loss. I was present for my 0-5 win only made the substitution to get the green pack.
With that said, a little background:
As you can see in my sig, I found a lot of early success. That was because I was very active in terms of finding quality nordgens. They also provided a lot of free packs to power train. With the changes to reduce the resources and nordgens and my unwillingness to wake up at 3am local time to find the nordgens, I found it hard to compete at the same level. Throughout that whole time, I used the sheet to set up my formation (no tactics yet). Early on, that was all I needed. At some point (I believe when associations started), it seemed that tactics were given much more weight. Winning wasn't as easy and I'd draw against significantly weaker opponents (some people call this a troll result...i felt it was due to wrong tactics). Given my personal state with the game (on the edge of quitting due to not being willing to do what was necessary to compete without paying), I decided to try to make the sheet spit out tactics that I'd like in order to reduce the amount of time I spent strategizing my tactics. Right now, the tactics it generates are close to the tactics I would choose. Of course, I'll find an error occasionally. I'll try out the tactic anyway and sometimes it works great and sometimes it's no good. The majority of games, I get some complimentary comment about a perfectly chosen tactic. Whenever I get some comment about having to change to high pressing or counter attack or whatever, I'll make some modifications to the tactics formulas. Again, it's not perfect and management during the game is still key to react to opponent changes. Playing with the formulas is a big part in keeping me interested in the game.