For example, at d=23 Critter 1.6a evaluated White's top 3 moves to be 94.f4, 94.g5, and 94.Nd2, all of which would have extended the streak a few more moves with the following lines:

1. [+1.42] 94.f4 f6 95.g5 Ng8 96.Nd2 Rb7 97.Qg3 Kh8 98.gxf6 Bxf6 99.Nf3 Re7 100.fxe5 Bxe5 101.Nxe5 dxe5 102.Kg1 Qd7 103.Ne1 Qd6 104.Nf3 Ba4 105.b5 Nc7 106.Rf1 Rf8 107.Rg2 Rf6 108.Rgf2 Rf8

2. [+1.42] 94.Nd2 f6 95.g5 Rb7 96.f4 Ng8 97.Qg3 Kh8 98.gxf6 Bxf6 99.Nf3 Re7 100.fxe5 Bxe5 101.Nxe5 dxe5 102.Kg1 Qd7 103.Ne1 Qd6 104.Nf3 Ba4 105.b5 Nc7 106.Rf1 Rf8 107.Rg2 Rf6 108.Rgf2 Rf8

3. [+1.41] 94.g5 Ng8 95.f4 f6 96.Nd2 Rb7 97.Qg3 Kh8 98.gxf6 Bxf6 99.Nf3 Re7 100.fxe5 dxe5 101.Bd2 Bg7 102.b5 Nb8 103.h5 g5 104.Ne3 Nd7 105.Nf5 Bxh5 106.Rf1 Qe8 107.Bc3 Ngf6 108.Nxe7 Ng4+ 109.Kg1 Qxe7

Of course, 94.b5 was also an option and, after 94...Nc7, they would have had the opportunity for another 50 meaningless piece moves to further extend the no-capture record. Then 144.a4 would have given them a further 50 moves, etc. At d=22 Critter evaluates the position after 94.b5 Nc7 at [+1.04]after either 95.g5 or 95.Qg3, still better than the 94.bxc5 that Rogoff chose, and also delaying the first capture for a few more moves.

And the "action" need not have been restricted to the q-side. Williams also had either ...g5 or ...h5 to work with after proper preparation, and with 50 piece moves in between pawn moves there should have been enough time for the proper preparation. Note that Rogoff need not respond immediately with either h4-h5 (in response to ...g5) or g4-g5 (in response to ...h5). Rogoff could have moved his pieces for 49 moves before either of these pawn advances. Finally, there was always the non-committal ...f6 to keep the ball rolling.

Perhaps the greater challenge with 50-move intervals between pawn moves would be avoiding a draw by repetition. Williams in particular has a limited amount of space to maneuver and it may perhaps be impossible to avoid the repetition of position of the pieces 3 times in between 50 pawn moves. Maybe some motivated person out there can take up the challenge and demonstrate that after, say, 94.b5 Nc7 that it is <impossible> for the position not to be repeated 3 times for the Black pieces, although it might require some cooperation from Rogoff since, with more space, he had more options to move his pieces. But, even if the 3-move repetition of position was forced, the rules require one or the other player claim the draw by repetition. In the absence of such a claim, the game could have continued, and they might still be playing it as we speak.

So, why did Rogoff break the non-capture streak at move 94? Did he finally get really bored or did he all of a sudden realize that he had something more important to do? Perhaps he just got hungry and wanted to go get something to eat. But in any of these cases he could have just made a non-pawn, non-capture move and claim a draw by repetition, ending the game almost immediately instead of playing on for another 13 moves. So these explanations don't seem to make much sense.

Therefore my theory is that since Rogoff was either 15 or 16 at the time this game was played, puberty finally set in. Chess has been known to delay puberty among chess-playing males (studies about chess-playing females are inconclusive) and according to his bio Rogoff was 6 years old when he learned to play the game and 13 when he took up the game in earnest. A long time sublimating normal hormonal urges, and these effects are cumulative. When Mother Nature finally took over, the sudden onset of testosterone created an irresistible urge to play the "aggressive" 94.bxc5. But 94.bxc5 dissipates most of White's advantage; at d=23 Critter evaluates the position after 94.bxc4 at [+0.41] following 94...Nxc5 95.Nxc5 bxc5 96.f4 Rxb2 97.Rxb2 f6 98.g5 Ng8 99.Qb1 Bb6 100.f5 Rb8 101.h5 fxg5 102.hxg6+ Kg7 103.Kg3 Nf6 104.Qd1 Ba5 105.Rxb8 Qxb8 106.Qc2 Bd7 107.Bc1 Qd8 108.Kf3 Qc8 109.Ne3 h5 110.Nd1 g4+ 111.Kg3 Be1+ 112.Kg2. Aaah, the impetuousness of youth!

Fortunately he was able to release his inner tensions by 94.bxc5. I'm afraid to think of the consequences had he not been able to do so and chose other means to release his inner tensions. Something similar happened to me except at a later age. Since I didn't learn the game until I was 11 or 12 the puberty-inhibiting effects of chess were not as strong, and neither was I as strong a player as Rogoff. So my inner tension release was not as urgent nor as well documented for others to see at a much later date.

Williams was older than Rogoff at the time this game was played, at least 19 years old, and the effects of a possibly-delayed puberty had subsided, stiff upper lip notwithstanding (he was born in Wales). But I suspect that he was disappointed at Rogoff's breaking the possibly prearranged agreement to set a record for the longest non-capture came that would never be broken due to lack of interest. He might even have described 94.bxc5 out loud as a "bitter disappointment", predating Fischer's similar comment after R. Byrne resigned their game in the 1963 US Chess Championship, and possibly inspiring it. As it was, a longest non-capture record-breaking attempt is probably achievable, should two players be sufficiently motivated to attempt to do so, perhaps under the influence of some super-Sofia rules being in effect.

click for larger view

interactively linked to Crafty End Game Trainer:
http://www.chessvideos.tv/endgame-t.... The ending should presumably be won: enjoy finding the win against the EGT if you have the patience.

White maintains opening advantage until 13. Rg1 loses about .6 for white (O-O was better).

16...Bf6? lost .25 (Nec7)
18. Bg5 lost it back (Bxg7)
20...Kh8? lost .75 (Nec7 again)
21. Bd3 gave .5 back (h4)
21...Nf6 lost .8 (to 1.5, Qe7)
23. Rb1 loses .5 (f3) but played it a move later gaining it back

Throughout the 20s after this, SF wants White to play h4, and black to play Bf6/Nc7. The analysis swings widely as these giants ignore these developing moves.

SF then wants white to move Qd7. Adding that to 28...Qe7, it seems that both players wasted a move. White is rated +1.58 with this continuation.

28. h4 h6 29. Kf2 Kh7 30. h5 b6 31. Kg2 Ne7 32. Rh1 g5 33. b4 Kg8 34. Nf5 Nxf5 35. exf5 cxb4

With 32. Qg2, white loses .75 and has descended into draw territory (Qd2, retains about a pawn advantage).

33...Bf6 undevelops his bishop for no reason, when SF wants Nc7. Black moves 34...Nc7 after 20 moves of SF's pleading!

35. Qf1 is a dead draw. At this point, SF wants b4 and Kg2 for white and Bg5 for black for several moves.

39...Bh4 is another major blunder, losing a theoretical pawn (Bxe3). The next move, black undevelops his bishop again to Bf6. At this point White is +2.1 with a powerful kingside continuation:

41. g5 Bg7 42. h4 f6 43. h5 gxh5 44. Nxh5 fxg5 45. Bxg5 Qf7 46. Nxg7 Qxg7 47. Qh2 Qf7 48. Be2 Nc7 49. b4 b6 50. Rh1 Rf8 51. bxc5 bxc5

But why would white want to do that? 41. Rb2?

Throughout the 40s, it's clear that black's bishop should have stayed at h4 instead of waltzing around. 44. Na2 lost a "grim" .7 (Kg2), but black's bishop wastes time. SF would have white develop Kg2 and pawn break f4.

50. Nf5 moves white back to draw territory (Nc3).

Then 51. Bf2? (a clear blunder per SF) gives black his first fleeting chance at a win -.5 (Nc3), which is squandered by ...Bg5 (gxf5).

53...Be7 (again undeveloping his dark bishop) puts white a pawn up (Bf4).

Through the rest of the 50s, SF wants to initially expand on the kingside with h5 and a rook on the h file, but after redirecting a rook to the b file continues its desire to get it's rim knight to c3.

Black continues to waste moves on the dark-square bishop, instead of moving knight to f6 as SF would like.

Seesaw continues through the 60s. SF has been demanding Nc3 nearly ever one of the last 25 moves.

Black, on the other hand, had multiple development options, Ne7, h5, cxb4, which it throws away for futile bishop moves. It appears knights are more valuable to SF in these positions.

73. Nc3. After 30 moves.

78. Ba4 was a -1 point error (Kg1), but ...Bc8 was worse (cxb4) as white's 79. Bc6 could force a white passed d pawn, giving white a 1.5 advantage in SF. White declined 80. Bxb7, returning to business as usual.

90...Na6 is a bad idea for black, losing .7 (Nf6), and again white must make a combative g5 to capitalize, but instead undevelops it's knight to a2.

93...Ne7 blocks the correct Be7, giving a +2 to white. SF would like white to respond with f4, which appears to be one of white's key moves in controlling the board.

<AylerKupp>'s megapost gloriously expounds on the tragedy of white's first capture, and SF concurs with his assessment.

Trading of the rooks began white's descent to a draw, SF attempted to avoid this with Nb3 or Ne2. 99. Bc2 would have robbed white's minor advantage if ...Bxc2.

SF doesn't say 104. Bc6? is a blunder, though what else would you call ignoring a free pawn? The pawn stays in play for white until the draw.

Many here have speculated on possible continuations (<David2009> is right on) after 106...Qa5, so I will not.