How to win the big games

I realise I could look in the tactics forum, but I'm partly doing this as a slight rant(not at the game, I think it's great!)

I'm Spurs in 2018, after a successful 6 years at Liverpool, winning the league every season, and have taken them from mid table to top 4 by selling off older players and buying talented young players that I'd mostly scouted at Liverpool but didn't sign as I had a world class squad already. This season, my second, I've played 17, won 11, drew 2(right at the start in the first 4 games) and lost 4. I think that bar Liverpool, I've got a first team to match any other in the league, but the 4 games I've lost have come at the hands of City, Chelsea, Liverpool and Arsenal(I was 2-0 up and then lost 4-3, so that I'm willing to blame on my tactics/teamtalk entirely) Whereas I've hammered the smaller teams(7 times I've scored 4 or more).

I tend to go to a slightly more defensive tactic against the big teams, changing my starting strategy from Attacking to Control, but am wondering if it'd be better to attack more from the off?

Also, I have a lot of younger players, regens(Bale is the only regular non-regen in my team, with Huddlestone, K.Walker and Defour as subs, though Defour has been starting due to an injury to my star midfielder), so I'm wondering how much age will have a part in it too, and how/if at all that links to the hidden important matches stat?

Just curious really. I've got Man Utd next and a win could take me into 2nd, though still 9 points behind my old Liverpool team(Guardiola took over, and won the league last year and is leading it this year with exactly the same team I used, he's riding on my success the bugger!). So I'd like to win it!

Maybe it's just a case of needing to tighten up (in terms of strategy and perhaps even creative freedom, mentality structure etc.)

Or perhaps you need to put less pressure on the team with your team talks. Just a couple of thoughts there.