The Power Of Two Checks

"NEVER miss a check - it might be mate" is attributed to Joseph 'Black Death' Blackburne.
Chess historian Edward Winter traces the aphorism back to a simultaneous display given by Blackburne in Birmingham in 1890.
What could be more powerful than giving check? Well, giving checkmate is certainly up there, and giving double-check is usually not bad either (but then both of these are also examples of giving check).
My database of my games has 26 examples of games containing a double-check.
Perhaps surprisingly, the double-checker only won 14 of the games, losing seven and drawing five. That is a score of 63.5%.
Here is the second-oldest example among my games.
Anthony D Brown (143) - Spanton (156)
Highbury (rapidplay) 1991
Evans' Gambit
1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.0-0 Nf6 5.b4!?
Captain Evans first played his gambit in a similar way in 1836, except that in that game Black played 4...d6 rather than 4...Nf6.
5...d5?!
The move ...d5!? is an interesting try against 4.b4, but here it is almost certainly inferior to 5...Bxb4.
6.exd5 Nxb4 7.Nxe5 Nbxd5 8.d4 Bb6?
Harry Pillsbury played the better 8...Bd6?! in a loss to Emanuel Schiffers in 1896.
Stockfish10 and Komodo10 reckon Black keeps his disadvantage to a minimum with 8...Be7 or 8...Bb4.
9.Ba3 Be6 10.Re1 Nf4?
Better is 10...c6.
11.Bb5+?
11.Qf3 is strong, as is the consolidating 11.c3. In both cases the black king makes a miserable impression.
11...c6

How should White proceed?

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12.Nxc6?
Unclear is 12.Bxc6+!? bxc6 13.Qf3, but the engines' 13...Qd5!? (13...Nd5 14.c4) 14.Qxf4 Bxd4 15.c3 Bxe5 16.Qxe5 Qxe5 17.Rxe5 0-0-0 seems to be at least fine for Black.
Also far from clear is 12.Nc3!?
12...bxc6?
The engines' 12...Qd5! 13.Nxa7+ Kd8 looks good for Black.
13.Bxc6+ Nd7 14.Qf3 Rc8 15.Qxf4 Rxc6 16.d5 Rxc2 17.dxe6 Nf6?
Better is 17...Qf6, but Black still succumbs to a double-check, eg 18.exd7+ Kxd7 19.Qa4+ Qc6 20.Qg4+ Kc7 21.Nd2!?
18.Qa4+ Nd7
Now comes double-check and mate.
19.exd7#

My most-recent game featuring a double-check came against a junior in August.
Spanton (1881) - Boris Stoyanov (1592)
Northumbria Masters 2019
Scandinavian Tiviakov
1.e4 d5 2.exd5 Qxd5 3.Nc3 Qd6 4.d4 Nf6 5.Nf3 g6!?
Kramnik, Caruana, Nakamura and Tiviakov are among grandmasters who have tried this, but the main move is 5...a6.
6.Bc4 a6 7.Ne5!?
The engines reckon 7.Ng5 is even stronger.
7...e6 8.Bg5 Bg7 9.Qf3

Black to make his ninth move

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9...Nbd7
An improvement on 9...Nc6?? 10.Ne4 Qb4+ 11.c3 Nxe5 12.Nxf6+ Kf8 13.dxe5 Bxf6 1-0 in  Davide di Trapani (2090) - Sergio Garofalo (1826), Modena (Italy) Championship 2012.
10.Ne4 Qb4+?
The engines give 10...Qxd4 11.Bxf6 Nxe5 12.Qf4 0-0 13.0-0 Qxc4 14.Qxe5 Bh6 15.Rfd1 with a strong attack for White.
11.c3 Nxe5
The game has transposed to di Trapani - Garofalo.
12.Nxf6+ Kf8 13.dxe5 Qxc4
Marginally better than 13...Bxf6, but still hopeless.
14.0-0-0 Ke7
Now comes double-check …
15.Ng8+ 1-0
… and it would have been mate, after 15..Kf8 or 15...Ke8, by 16.Rd8#.

Ponzing About (part four)

José Capablanca - MPs
London 1919
The future world champion played against future prime minister Andrew Bonar Law, who was consulting with two other MPs (I have not been able to discover their names).
1.e4 e5 2.Nf3 Nc6 3.c3 d5
Bonar Law is said to have been a strong amateur (Edward Winter has a fair bit of chess information about him: http://www.chesshistory.com/winter/extra/bonarlaw.html), so it is not surprising the MPs should play what is probably Black's sharpest line.
4.Qa4 dxe4!?
Black has a lot of choice here, eg 4...f6, 4...Bd7, 4...Nf6, but the text is the one move against which White scores a high percentage. Stockfish10 and Komodo10 reckon ...dxe4 is a mistake (they flash red), but engines' early-opening assessments are much less reliable than their middlegame judgments.
5.Nxe5 Qd5 6.Nxc6 bxc6 7.Bc4 Qd7 8.d3!?
Chigorin played 8.0-0 in wins against Steinitz and Bird at London 1899.
8...exd3 9.0-0
9.Bxd3 is also possible as 9...Qxd3? loses the exchange to 10.Qxc6+ etc.
9...Bd6 10.Bg5
The engines much prefer 10.Nd2, which was Ljubojevic's choice in a draw against Karpov at the 1975 Vidmar Memorial.
10...Ne7 11.Nd2 0-0 12.Bd3 f6
Not 12...Bxh2+? 13.Kxh2 Qxd3 14.Bxe7 Re8 15.Nf3 Rxe7? 16.Rad1 (threatening a back-rank mate) Qe2 17.Rfe1.
13.Qc4+ Kh8 14.Be3 a5 15.Bc2 Nf5
If 15...Ba6, then 16.Qh4.
16.Bxf5 Qxf5 17.Qxc6
White has won a pawn but Black has active play.
17...Ba6 18.Rfe1 Rfb8 19.Ne4 Be5 20.Nc5 Bb5
White found a way to defend the b pawn without a) weakening the c pawn by playing b3, or b) playing the passive Rab1.
21.Qf3 Qxf3 22.gxf3 Bc6 23.f4 Bd6 24.b3
White's c pawn cannot easily be attacked in this position, and so is not weak.
24...Rb5 25.Ne6 Rh5
Vigorous play by the MPs. White is still a pawn up, but the bishops are powerful and White has kingside weaknesses.
26.c4 Rh4 27.c5 Rg4+ 28.Kf1

Can you find a good move for Black?

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28...Bb5+?!
Tempting, but wrong. Black wins the exchange, but at too high a cost. It was better to retreat the dark-square bishop.
29.Re2 Bxe2+ 30.Kxe2 Be7 31.Nxc7
White's passed c pawn is very powerful, not least because the black rook at g4 cannot easily get to the queenside to help combat the passer.
31...Rc8 32.Nd5 Bd8
Not 32...Bxc5? 33.Rc1, but the engines much prefer 32...Bf8.
33.Rc1 Rh4 34.c6 Rh5
34...Rxh2 loses a piece to 35.c7.
35.Rc5 Bc7 36.a4 Rxh2?
This loses quickly, but the engines' 36...h6, removing a possible later back-ranker, is met by 37.Rb5, eg 37...Rxh2 38.Nxc7 Rxc7 39.Rc5, followed by Kd3-c4-b5 etc, when White's queenside play is quicker than Black's kingside counterplay, although it is still  a game.
37.Nxc7 Rxc7 38.Rxa5
Possible as 38...Rxc6?? loses to 39.Ra8+.
38...h5 39.Rc5 g6?!
This is slow, but 39...h4 would make no difference to the outcome, eg 40.b4 Rh1 41.b5 Rb1 42.Kf3, when the h pawn is stopped and White wins easily on the queenside.
40.b4 Rh1 41.b5 Rb1 42.a5 h4 43.b6 Rxc6 44.Rxc6 h3 45.a6 h2 46.a7 1-0
Black can queen first, but White is mating, so the MPs resigned.