The middlegame is BY FAR the most important phase

I haven't done this but I'd wager if a person played an engine set 500 points below them (say 1500 if you're 2000) in the opening (say til move 15) AND in the endgame (after move 40) but full strength (3000 or whatever) in the middlegame they would lose say 95%+.

But the reverse (where opening & endgame were full strength) and middlegame was -500 I'd guess they'd win at least 50%

If I had unlimited money I'd throw people a few bucks to run this experiment.

middle game > endgame > opening

Actually.i agree,

Play the opening like a book, the middle game like a magician, and the endgame like a machine. - Spielmann

The endgame is just equally important because people tend to neglect it and nothing comes after it

@Cedur216 said ^

The endgame is just equally important because people tend to neglect it and nothing comes after it

It's important but you need to get there. It's a big deciding factor amongst similarly rated players. A 1600 who's much better at the endgame than other 1600's won't stay in that range long but as they rise up they'll likely get outplayed in the middlegame more often.

there is no most important phase

,,in the opening you want to get an advantage. In the middlegame you think you have an advantage. And in the endgame you realize you have a lost game''

Siegbert Tarrasch,José Raúl Capablanca

I think most games end in the middlegame when your a club player so I understand why you think it is the most important

I've lost too many games in the endgame

"Middle game, separates the Men from the Boys" -:]