Nov 152017
 

While wearing my ICCF Tournament Directors hat, I discovered something I had not previously been aware of. There are some Queen endings where two connected passed pawns aren’t enough to win. This was drawn to my attention when a game in an event I was directing was drawn after one of the players made a tablebase claim (In Correspondence Chess a player can claim a draw or win if the position is assessed as such in a 6 piece or less tablebase). While the claim was perfectly valid I did feel a little sorry for the other player involved.
Even without the advantage of modern technology, the game may well have been drawn anyway, as it turns out there have been some precedents.  In 1985 Boris Spassky was defending exactly the same position against Zoltan Ribli and successfully held. Here is the game in question, with Black having a completely drawn potion by move 82.

Ribli,Zoltan (2605) – Spassky,Boris V (2590) [A30]
Candidates Tournament Montpellier (4), 1985new PgnViewer( { boardName: “game796”, movesFormat: “default”, pgnString:’1.Nf3 Nf6 2.c4 b6 3.g3 Bb7 4.Bg2 c5 5.Nc3 g6 6.O-O Bg7 7.d4 cxd4 8.Qxd4 Nc6 9.Qf4 Rc8 10.Rd1 d6 11.Bd2 O-O 12.Rac1 h6 13.b3 Qd7 14.Nd5 Nxd5 15.cxd5 Ne5 16.Nxe5 dxe5 17.Qh4 g5 18.Qh5 Bxd5 19.Bc3 e4 20.Bxe4 e6 21.Bxg7 Rxc1 22.Rxc1 Kxg7 23.Rd1 Qe7 24.Bxd5 Rd8 25.e4 exd5 26.Rxd5 Rxd5 27.exd5 Qe5 28.Qd1 Kf8 29.Qd3 Ke7 30.Qc4 Kd6 31.Qc6+ Ke7 32.Kf1 Qa1+ 33.Kg2 Qe5 34.h3 Qe4+ 35.Kh2 Qd4 36.Kg1 Qd1+ 37.Kg2 h5 38.a4 g4 39.Qc7+ Kf6 40.Qf4+ Kg6 41.Qe4+ Kg7 42.h4 a5 43.Qe5+ f6 44.Qf5 Qd4 45.Kh2 Qd2 46.Kg2 Qd4 47.Qe6 Qd3 48.d6 Qf3+ 49.Kg1 Qd1+ 50.Kh2 Qf3 51.Qe1 Qd5 52.Qe7+ Kg6 53.d7 Qd4 54.Qe8+ Kg7 55.Qe3 Qxd7 56.Qxb6 Qd2 57.Qe3 Qc2 58.Kg2 Qc6+ 59.Kg1 Qd5 60.b4 axb4 61.Qe7+ Kg6 62.Qxb4 Qd1+ 63.Kh2 Qc2 64.Qd4 Qc7 65.Qe4+ Kg7 66.Qa8 f5 67.Qd5 Qa7 68.Qxf5 Qxa4 69.Qxh5 Qe4 70.Qg5+ Kh7 71.h5 Qf3 72.Qg6+ Kh8 73.Qh6+ Kg8 74.Qf4 Qd1 75.Qg5+ Kh7 76.Qf5+ Kg7 77.Qe4 Kh8 78.Kg2 Kg7 79.f4 gxf3+ 80.Qxf3 Qc2+ 81.Kh3 Qd2 82.Qg4+ Kh8 83.h6 Qb2 84.Kh4 Qh2+ 85.Kg5 Qxh6+ 86.Kxh6 1/2-1/2′, pauseBetweenMoves: 500, pieceSize: 29 } );

The injustice of it all
Source: Chessexpress