I remember Harry saying something along the lines of that tactics are a minor part of football and the majority of a game is won by who has the best players on the pitch. I tend to agree with him to an extent, because while I do see value in having a "system", you need the right players to play it. No matter what Brendan Rodgers or AVB at Chelsea and the start of last season may have thought, a "system" won't get results on its own, it can actually be detrimental to your chances of success.
Last season, we implemented the high line and the high pressing game. Bizarrely, AVB tried playing these tactics with Friedel and Gallas in the side and we conceded a lot of poor goals in the early part of the season. Once we'd brought in Lloris and Dawson, things improved massively until Sandro's injury. Sandro was great at not only the pressing aspect, but also getting back and covering when we were being hit on a counter attack. They say attack is the best form of defence, and by using these tactics we were able to force the play into the opposition half and away from our goal.
Now, I feel we have the players to effectively employ these kinds of tactics. Sandro is coming back to fitness, but we also have replaced Parker and Huddlestone with Paulinho and Capoue, meaning we have a faster, more physical presence in the middle of the pitch to hassle the opposition off the ball and press them back into their own half. We can physically dominate most teams and make it difficult for them to get near our goal. The improved physical presence has also meant we are conceding less from set-pieces, which became a big problem particularly in the final third of last season.
But crucially, I think another major improvement to our defence has been that we retain possession far better now. Parker could do that swivel and pass sideways/backwards thing, and Huddlestone could spray long passes out, but having the likes of Eriksen and Paulinho involved has meant we are far greater at moving the ball around quickly and effectively. Here is our possession % in the last few games:
Cardiff - 63%
Tromso - 59%
Norwich - 68%
Arsenal - 57%
Tiblisi (H) - 64%
Tiblisi (A) - 56%
Crystal Palace - 53%
Only in one game, against Swansea, the team who play arguably the most patient and possession based football in the league, did we have less possession than the opposition, even then it was 49%. It's quite simple, if the opposition can't get the ball off you, they can't score!