I would like to differ on this. It's getting harder and harder to maintain dominance. Kasparov was the one to hold the longest. Magnus, even though he is one of the best ever, is already losing out to Alireza in bullet, blitz and even almost in classical.
Chess theory has a new Renaissance due to neutral networks and we will see newer GM's adapting to it.
This is not how I see it. Carlsen lost one insanely long online bullet match on lichess.
He narrowly lost an online banter blitz match. This is not blitz, since also you have to talk while playing, which does not seem to suit Carlsen's personality.
In classical, you can often "almost lose", except that Carlsen does not "actually lose", as exemplified by his ongoing record non-loss streak.
People are reading a bit too much into this loss. It is a big deal that someone was able to beat Magnus Carlsen at any time control, especially in this era where Magnus has seemingly reached a new level of chess skill, but bullet is by far the the easiest for a champion to make a mistake or series of them. Magnus is ridiculously strong at bullet but I’ve watched his live-streams and sometimes he blunders really badly, that’s just part of bullet. Although he is incredibly strong at bullet, probably 50-100 points higher than the world #2. Anyone not a high ranked GM wouldn’t stand a chance of beating him in a series of more than 5 games. But I’ve seen him lose to players he is obviously better than. He’s the #1 so they try their hardest. Nothing comes easily for Magnus.
The classical time control chess is boring. It really feels like an exercise in memorization.
I stopped watching those as almost every tournament ends in armagedon. Its a statement of the incredible skills top players poses, but its incredibly boring to watch draw after draw.
Quicker time controls are more dynamic and allow to play subpar move to throw off your opponent. Often you can see some crazy attacks.
I watch a variety of games on Twitch, and I am fairly sure that no player would claim they play optimally while commentating themselves and explaining their thought processes.
I think if anyone has benefited from the coming of AlphaGo and Leela, it's Magnus himself. 2019 was such a renaissance for him partly because all these intuitive positional lines with pawn sacrifices opened up, and I felt in the years previous to that that his love for the game seemed slightly on the wane as he regularly became mired in others' Stockfish prep (while still being able to mostly pull it out due to endgame technique).
In fact, it was Magnus himself (currently 29 years old, as of April 2020) who said his favorite chess player was himself, when he was around 23. That Magnus apparently saw things on the board that current (overwhelmingly dominant) Magnus can't any more. So even in chess there's a physical prime, just like in pretty much any other sport.
He said that (jokingly) before his fabulous 2019 year.
Right now he's spending a lot of time promoting chess24 with banter blitz, hanging around on lichess playing 100 games bullet matches, commenting on chess24 and other things that would profoundly ruin anyone else's concentration.
So, no big deal if he very occasionally loses (online!) games.
I am really curious if we are going too see players adopting AlphaZero tactics. Games I saw goes so against current intuition and it would be interesting to see chess evolving.
Current crop of GMs benefited greatly from short feedback loops by using computers, but they still operate in explored problem space.
For what it's worth, Magnus has recently hit an all-time ratings high after a very, very slow decline over the last 5 years. And he attributes his recent bump to studying the AlphaZero games.
Magnus is so incredibly strong that people think he's about to decline when suffering one (1) loss from another rising star in a niche online format. This is like when Capablanca didn't lose a single game between 1917 and 1924 and everyone acted like "the Schachmachine ist kaputt" when he broke his streak. The fact is that competition is incredibly tough and differences betwene player levels are imperceptible to all but the very most trained eyes. In fact that's why championships need so many games and tie-breakers - the people are so equal in ability that the most likely result from a match between to top level players is a draw.
He is. Carlsen is a unique player in many respects and he usually comes back even stronger from losses. To say that he is "losing out" to someone is a bit premature I would say.
Chess theory has a new Renaissance due to neutral networks and we will see newer GM's adapting to it.