The middlegame is BY FAR the most important phase

It depends on the rating I'd say, the higher the rating, the later advantages are converted from what I've seen. A beginner may hang pieces in the opening, as one gets intermediate like 1400-1500+, they begin to lose due to subpar middlegame strategy and deep tactics, and the higher rated players like 2100 to super GM tend to slowly grind players down in long endgames and converting tiny advantages. Just look at the best players: Carlsen, Kasparov, Karpov, etc. Many of them won by being great at positional grinding. But that's just some stuff I've noticed in general.

"The middlegame is BY FAR the most important phase"

No. The phase in which the decisive blunder was made (i.e. the phase in which the outcome of the game was decided) is by far the most important phase.

I like to divide the game in four elements instead of three phases. These are, in order of importance: Tactics, Endgame technique, Strategy, Opening theory.
Tactics are everywhere from the opening to the endgame, and they can decide the fight right away.
The middlegame might be the most important phase just because it usually has more and more complex tactical posibilities than the other phases.

I've certainly seen games where the middlegame was just strategic positioning with the actual tactics coming at what could more accurately be described as the endgame, especially at the higher level. Also I'd like to point out that it also varies depending on what one considers to be the "endgame", as the line can be less stark at times. Also, at lower levels, many important tactics occur in the opening. So this is essentially my previous sentiments applied to your tactic theory.

'Opening: is not an important part of the game, especially with White, just play what you know, or if you don’t want to spend your time into learning openings, just play the London system.' - IM Khagan Ahmad - World Youth Under-16 World Chess Champion 2026

'Before the endgame, the Gods have placed the middle game.' - Tarrasch

we just makin qoutes from others XD

i do believe as well, as the middle game can determine your endgame if you use any advantages to your use.

A chess player can still be executing an opening plan while their opponent is already playing for an endgame. The phases of chess are not synchronized between the players, even if software makes it appear that way.

There are two players and two game plans happening at the same time. A player could be defending perfectly in the middlegame while their opponent is already planning how to win the endgame.

The end of a player's phase should reflect the moves they have actually made. Each player can have a pawn structure that comes from a different opening, and those structures can remain relevant for different lengths of the game. Their opening plans can therefore end at different moments.

The engine only knows the position created by the moves that have been played.

@tpr said ^

'Opening: is not an important part of the game, especially with White, just play what you know, or if you don’t want to spend your time into learning openings, just play the London system.' - IM Khagan Ahmad - World Youth Under-16 World Chess Champion 2026

'Before the endgame, the Gods have placed the middle game.' - Tarrasch

well said almost sounds like something i would have said just joking ;)

With so many engines, perhaps the game isn't about finding the perfect pv1 move anymore. It's about understanding the purpose of the position, knowing what can still matter, taking the risks worth taking that engines don't do and figuring out where our pieces truly belong.

Chess doesn't necessarily have a better phase. Though, I like the endgame phase the most. How quickly can I end a game is often in my thoughts. Here is a graph of the chess phases, so that you can see one graph for black and another for white and the middle game. Black was behind in development.

"Every now and then someone advances the idea that one may gain success in chess by using shortcuts. 'Chess is 99% tactics' - proclaims one expert, suggesting that strategic understanding is overrated; 'Improvement in chess is all about opening knowledge' - declares another. A third self-appointed authority asserts that a thorough knowledge of endings is the key to becoming a master; while his expert-friend is puzzled by the mere thought that a player can achieve anything at all without championing pawn structures.
To me, such statements seem futile. You can't hope to gain mastery of any subject by specializing in only parts of it. ..." - FM Amatzia Avni (2008)