KEG: As percyblakeney notes, Blackburne had a fine tournament in London 1899. He scored the only win against Lasker and beat Pillsbury twice. This game, however, was one of his worst performances in this event, and one of Steinitz' best games in the tournament.
Blackburne made so many awful moves that a complete catalog of them would be pointless.
Blackburne should have seized the initiative with 14. e4. Instead, his 14. 0-0 allowed Steinitz to strike first with 14...e5.
Also weak was Blackburne's 16. h3 (he should have played 16. h4) to which Steinitz should have replied 16...h4. After Steinitz' actual 16...g5, Blackburne cleverly played 17. e4, after which 17...dxe4 would have lost to 18. Nc4 and if 18...Qd8 19. Rd1. Steinitz didn't fall for that one, but after his 17...Be6 (best) Blackburne had approximate equality.
Blackburne's plan beginning with 21. a5 was faulty, and Steinitz' position was winning after that (Blackburne should have played 21. Qd1).
Beginning with move 23, Blackburne simply fell apart. 23. Nc4 was vastly inferior to 23. Rad1, and he definitely should have played 24. Bh2 before Steinitz got in 24. f4.
Blackburne's 26. g3 effectively smothered his own position (he was lost anyway, but this was suicide).
The Tournament Book says that Steinitz should have buried Blackburne's bishop with 26...f3, but Steinitz' 26...0-0 was even more crushing.
Blackburne's 27. gxf4 was hopeless, as was his 28. Bf1.
The remainder of the game does not warrant discussion, except for the bizarre finale in which Blackburne--presumably as a joke--decided he wanted to Queen a pawn before resigning. He got his wish with 45. a8(Q), but Steinitz now had mate in four beginning with 45...RxR+.
Hard to believe this was the same Blackburne who had brilliantly defeated Lasker in round 4 and who bested Pillsbury twice.