Gengistger White, Moonbus Black, notes by Moonbus

This is a serious positional error: it weakens the Black KP. I played it for tactical reasons, thinking I could keep the White B locked in long enough to get some counter play somehwere else on the baord.

This advanced KP will prove to be a critical outpost for White's pieces: Black has lost control over his own Q3. This shows up the weakness of Black's advanced KBP: he would have needed the KBP to challenge the advanced White KP, but now he cannot.

A second bad mistake. The Black K belongs on KB2 to try to hold the weakened KP. He will waste a tempo getting there later.

At this point I imagined that I could get some sort of attack going against White's K position with rooks on two open files.

A third bad mistake; nothing will come of this pseudo-attack. White will soon proceed with his own attack instead.

Ouch! There is no dislodging this rook, which paralyzes Black's position. Black will be defending a cramped position from now on.

Black immediately switches to defensive mode, trying to shore up the critically weak KP.

Ouch again. This shows up the error of Black' s 26th move (advancing the QNP): now White has a connected passer.

Over-protecting the weakened KP. Loss of tempo, see earlier note to Black's 0-0.