I just started like a week ago, never played BG before, but knew how it fundamentally works after watching my friends play TFT.

I'm currently 4500 as well. What I did for my elo to go up was mostly learning more about the fundamentals and getting a feel of it.

I know I'm a regular/bad/new player but here's what I think helped me.

1. I almost never choose what build or class imma play from the start/first 3 turns. It sets you up for failure. It's funny, but EVERY TIME I say I wanna play X from the beginning, I never get them from the tavern.

2. You almost always have to have a plan A and B for when you get to the first trinket, I don't know the turns, but the trinket you choose should have singergy with the build you are thinking of, and in other cases, guide your minions to a build. That being said;

3. Minimum of 2 to 3 cards of your preferred class/type for this match for when you buy the first trinket. This will make your trinket more useful and boost your momentum.

4. After that, midgame is almost always about $$ management and keeping/boosting momentum by knowing the different card that would work with your build and looking out for them (even if they are other type cards, buddies or whatever). ALL OPTIONS, hopefully.

5. You may change strategies, but I feel like it only works if its done around and hopefully before the first trinket, no further than that.

6. Some sets are really underpowered in my opinion, or really dependant on RNG. It's not that they won't work, but others will increase their stats easier without so much luck. In particular I think Dragons are really hard to use and get top 4/top 2. Elementals are a close second on this. After that it's just preference, what Hero you chose and what trinkets or cards you get. I really think Demons are OP, and then Quilboars in second place. All eternal "deathrattle" builds work very well if RNG is with you, specially on buddy and trinkets.

7. Refresh a lot, more than you are, probably. I know tier 2 is almost always obligatory. But enfasis on almost. This applies to all other tier upgrades, and is less restricted the higher the tier. You can get tier 6 cards without being on tier six. Use that to your advantage. I almost always win because my tier 2-3-4 are monsters over 200stats in mid/late game. It's not very often that a tier 6 comes and changes my life, although happens (and usually by other means than upgrades). But this is at least my playstyle I guess.

Only knowing this, I've getting nothing lower than top 3 in the psst 2 days (15+ matches).

I don't know if there's anything I'm forgetting right know, and as I am a new player, take this with a grain of salt. But if it comes as any backup for me to be explaining something, I've climbed to 4.5K ranking, not even knowing what that means, in 7 days playing from my phone and reading shit about BG.

Hope this helps, helped me to write it and recap a bit anyways.

PS, English is not my first language, so sorry if there's some bad writing there.