Lasker's Spanish Inquisition (part three)

AFTER his loss to Steinitz with 5.d4 in a Spanish Exchange in their first world championship match, Lasker successfully switched to 5.0-0 for several years.
Then in round nine of Cambridge Springs 1904 he used 5.d3 to beat Mikhail Chigorin in a queens-on middlegame.
Five rounds later he returned to his old favourite.
Lasker - Jackson Showalter
1.e4 e5 2.nf3 Nc6 3.Bb5 a6 4.Bxc6 dac6 5.d4 exd4 6.Qxd4 Qxd4 7.Nxd4
This position had quickly been established as a tabiya in the 5.d4 line. The real game begins now.
7...Nf6!?
The first example of this move in ChessBase's 2020 Mega database. Chigorin adopted it the following year, but it has never eclipsed 7...Bd7 or 7...c5 in popularity.
8.f3 Bd7 9.Be3 0-0-0 10.Nd2 Re8 11.Kf2
Lasker generally kept his king on the kingside in 5.d4 lines, but was much more likely to castle long after playing 5.Nc3.
11...g6 12.Rad1 h5 13.h4 c5 14.Ne2 b6 15.Rhe1 Bc6 16.Bf4 Bg7 17.Nc4 Nd7 18.c3 Bb5 19.Ne3 Ne5 20.Bxe5!?
Giving up his remaining bishop - a double-edged decision. On the one hand, White gets nearer an endgame, where he hopes his better pawn-majority will prove decisive. On the other hand, the bishop-pair tends to work best on a less-cluttered board.
20...Bxe5 21.g3 Bg7 22.Nf4 Rd8 23.Nh3 Rxd1 24.Rxd1 Rd8!?
The same double-edged considerations apply as at move 20.
25.Rxd8+ Kxd8
Stockfish10 reckons White is better, but Komodo10 rates the position as dead-equal.
26.Ng5 Be8 27.f4 c6?!
The engines reckon this is a mistake. They want Black to play 27...Ke7, again differing as to whether White is better.
28.e5 b5 29.b3 Bf8 30.c4
White's queenside pawn-formation means Black can never undouble his c pawns by normal means.
30...Be7 31.f5?!
This seems impatient. Probably better was 31.Kf3, and if, as in the game, 31...Bxg5, then 32.hxg5 leaves Black weak on the dark squares. Black may be theoretically OK, but in practice these positions are easier for the player with the knight.
31...Bxg5 32.hxg5 Bd7?!
A better defence seems to be 32...gxf5 33.Nxf5 Bd7 34.Nd6 Ke7, or possibly the immediate 32...Ke7.
33.e6
Possibly even stronger is the engines' 33.g4!? hxg4 34.e6 fxe6 35.fxg6, eg 35...Ke7 36.Nxg4 Kf8, when both 37.Ne5 and 37.Nf6 look to be winning.
33...fxe6 34.fxg6?!
This allows a successful defence, whereas creating a protected passed pawn with 34.f6 gives very good winning chances.
34...Ke7 35.Kf3 Be8 36.g7 Kf7 37.Kf4 Kxg7 38.Ke5 Bg6
White's king invades the black queenside, but Black's bishop returns the compliment.
39.Kd6 Bb1 40.a4
Or 40.a3 Ba2 41.Kxc6 Bxb3 42.cxb5 Ba4 43.Kxc5 Bxb5 with a draw.
40...Ba2 41.Kxc6 Bxb3 42.axb5 axb5 43.cxb5 Ba4 44.Kxc5 Bxb5!
Maybe this is what Lasker missed at move 34.
45.Kxb5 Kxg6 ½–½
A draw was agreed as Black easily liquidates White's pawns.