Update on the Twilight Zone

[Ed Gilbert]

In 2001 and 2002 I was testing a 6-piece version of kingsrow by playing it against some of the best mail players on the Banks Master Ladder. At that time the Twilight Zone was not very well understood. Some of the published play on it was incorrect, and a lot of games were won and lost in this one ballot. I remember at one point there was a rumor going around among some of the players that the TZ was actually a forced black loss.

I think the TZ is well understood now. After the programs with automated book generators started playing the 7-16 defense it became a bit easier to defend. But the 8-15 defense is still a very difficult line. After 23-18, I think 3-8 is now published to draw, and perhaps 6-9 also. I don't have the ID booklets for the last couple of years, so I don't know what has been published very recently. The 800k position opening book that I started distributing 1-1/2 years ago shows 3-8 as a draw, with 6-9 looking like it probably draws, and 7-11 looking this way also, but with a slightly worse book score. The propagated book scores are -8 on 6-9, and -10 on 7-11. Alternatives such as 15-19 and 5-9 are expanded only to the point where they don't look advisable, but cannot be identified as clear losses.

I have always been a little curious about the absolute loss or draw values of these TZ defenses. Recently I put the book generator to work on it with kr/10, and I expanded every black response after 8x15 23-18 until a very clear result was obtained. The results are in the book10 file that is now at my web site. I am much more certain now that 3-8, 6-9, and 7-11 are clear draws, and all the remaining black moves are very probable losses with book scores of -100 or worse.

Link to the kingsrow web site

-- Ed

[Macb]

Hello Ed,

Thanks for the play on the "Double Cross" and "The Twilight Zone". Ed, in 1996 Bob Podoff from New York and I worked on this 6-9 defense of the Twilight Zone and we developed over 2,000 variations on this defense. At that time I also thought that 6-9 would draw, however, Bob and I came up with one attack out of the 2,000 variations that would defeat 6-9. I will search for my notes on 6-9 defense but I may have thrown them away after discovering one of the variations wouldn't draw. I will search my house over and see if I can find my notes that I developed then. I will be definitely interested in seeing your draw on the 6-9 line. Yes, 3-8 does draw but you must know the excat order of moves to draw. The top mail players in the world knew about the 3-8 draw of the Twilight Zone but we didn't know about the 7-16 draw that Kingsrow developed. Now, I only use the 7-16 line as there are more cooks to defend against on the 3-8 line, especially man down wins for white when red goes wrong. Ed, thanks for providing the checker world with so much new play on the openings.

[Ed Gilbert]

Hi Mac,

I hope that you can find your 6-9 analysis, it would be interesting to see how it compares to the play in book10. I checked back in my file archives to see if I played 6-9 against Bob Podoff in our Banks Ladder match. I found the pdn file of the games, but unfortunately kingsrow took the 7x16 capture so we didn't go in that direction. I also noticed that Bob lost the game in which he played the weak side of the TZ, taking the losing 5-9 defense. This is an example of what I meant about the state of knowledge about the TZ back in 2001. Here is the game:

[Event "Game 1, Banks Master Ladder Games"]
[Site "E-mail play"]
[Date "August 23, 2001"]
[Round "3"]
[Black "Bob Podoff"]
[White "KingsRow"]
[Result "0-1"]
1. 9-13 24-20 2. 11-16 20-11 {Twilight Zone} 3. 8-15 23-18 4. 5-9 18-11 5. 7-16 22-18 6. 4-8 25-22 7. 10-14 28-24 8. 14-23 27-18 9. 3-7 29-25 10. 1-5 24-20 11. 16-19 18-15 12. 7-11 32-28 13. 11-18 22-15 0-1

[Michael Holmes]

Can you post the best line here for red for this TWZ line.
Thanks,
Michael