From e4 to d4 evolution. Who's behind it? Alpha Zero !?

Now days top level chess and other strong players strongly prefer d4 opening instead of e4.

Of course nowe4 also very possible, but if we compare to the past era, where e4 was best by test , most popular etc... now we more and more see d4 best by test .

My question is who's behind that change? Do you think alpha zero plays a big role in a d4 opening?

Strongly prefer d4?

Candidates tournament had (this is rough estimate) 30% of games started with e4, 60% started with d4.

d4 has been slightly preferred at the top level for a long time, but even so, I think Alpha Zero has practically zero impact on how we play chess. Mostly it impacts non-player's imaginations. It's not even as if it was that good. It scored 100 elo over a weakened old version of stock fish. Not much of a chess victory (but a tremendous AI victory as it also taught itself Go and Shogi).

Anyway, it used to be the Petroff, but these days it's the Berlin that makes 1.e4 undesirable to top players who view having white as their only good opportunity of getting winning chances.

Interesting

Alpha Zero is not part of theory improvements (it has played against a weakened stockfish without its opening book IIRC). It was mainly a huge advertisement for Google.

1.d4 is not played more than 1.e4 at top level, that was just a trend in the post-Kasparov era that ended with Carlsen.  

The past era? d4 was considered best by test in Capablanca's times. 

No it wasn't, Capablanca, Alekhine, and Lasker were just obsessed with the QGD for a period.  Even all 3 of them played 1.e4 more than 1.d4.  Fast forward to now, and look at the top 15 players, most are primarily playing 1.e4, with a few switch hitters and a few 1.d4 devotees (Aronian, Mamedyarov).  

I think no one would state one is objectively better than the other nowadays, anyway.

True.

Oh, cmon, that song again, «SF played without book opening». It was crushed in middlegames, not in the openings, which were all sound, none Damiano or Englund was played. Stop repeating like a parrot what you read on some dark conspiracy-maker website

First of all SF playing without his opening book is a verifiable fact.

And among the conspiracy-maker websites I've read this, you'll found this very website chess.com and its forum, where this was stated by experienced strong correspondence and titled players. You know, people who have to use these softwares all the time besides other things.