Ways to lose 18-15

* Attacking 18-15 with 4-8! is a dangerous line, currently winning many games. . The run-up is 11-16, 23-19, 16-23, 26-19*, 8-11, 27-23, 11-15, 22-18, 15-22, 25-18, 9-13, 29-25*, 13-17, 21-14, 10-17, and 18-15 forming diagram.
4-8 immediately threatens 7-11 at every move and leaves the option of 5-9 or 6-9!-then the option of 9-13 or 9-14, all deadly threats, depending on white plays.
Against 4-8, the logical continuation is to continue with 24-20, as if Red had played Chinook's 5-9 attack, and GET THE NECESSARY 24-20-28-24 "lineup", mentioned earlier. That is necessary to draw the opening, and prepare life saving 15-10 and 15-11 moves. However, after 24-20*, White must get the "lineup" in a delayed way. Red will, on the other hand , punish or prevent it, with deadly 7-11 attacks. So on we go-from the diagram, Red to play. 4-8*, 24-20, 6-9! (the 1st deadly option) and now several ways.
1. 28-24, and the deadly 7-11*, 25-21, 11-27, 21-14, 9-18, 32-14, 3-7* wins. OR 28-24, 7-11*, 32-27, 11-18, 9-18, 31-26, 1-6, 19-15, 3-7, 24-19, 7-11*. RW

2. 31-26, 17-21, 28-24, 7-11*! (again) 32-27, 11-18, 23-14, 9-18, 26-23, ( 26-22, 5-9, 22-15, 3-7, 27-23, 7-10, 15-6, 1-10. RW) 8-11, 23-14, 2-7, 25-22, ( 27-23 7-10x also) 7-10, 14-7, 3-10 RW.

3. 31-26, 17-21, 25-22, 9-13*, 32-27-3A, 7-11*, 15-10-3B, 2-7, 19-16, 7-14, 16-7, 3-10, 20-16, 12-19, 23-16, 8-12, 16-11, 10-15, 27-23, 15-19, 23-16, 12-19, 11-7, 5-9, 7-3, 21-25 etc. RW

3A. 22-18, 7-11*, 15-10, ( 26-22 5-9 wins and if 28-24, 2-7, 32-28, 5-9 wins. If 32-27, 1-6, 19-16 etc. 7-10 etc .wins) 2-7, 18-14, 13-17*, 19-16, ( 32-27 1st no better) 12-19, 23-16, 8-12, 32-27, 12-19, 27-24, 11-15, 26-22, 17-26, 30-16, 21-25, 24-19, 15-24, 28-19, 5-9*, 14-5, 3-10 wins this bridge.

3B. 22-18, 1-6, 27-24, 2-7, 19-16 etc. 7-11 is #4.

4. 31-26, 17-21, 32-27, 9-14*! 27-24-4A, ( if 19-16, 12-19, 23-16, 7-11*, 16-7, 2-18*, 26-22, 5-9*, 22-15, 14-18*, 28-24, 9-14*, 24-19, and 1-6* stops and man down draw. Red now steals the piece on 25. If 20-16 now then 8-12(best) followed by 6-9 etc. RW) 7-11*, 15-10, 11-15, 25-22, 5-9*, 20-16, 8-11*, 16-7, 2-11, 24-20, ( 22-17, 11-16*, 17-13, 16-20, 13-6, 20-27, 19-16, 12-19, 23-16, 14-17*, 6-2, 27-31, 26-23, 31-27, 23-19, 15-24, 28-19, 27-23, 19-15, 23-19, 16-11, 19-23* wins) 15-24, 28-19, 11-15, 19-16, 12-19, 23-16. The resulting bridge is similar to our bridge study in Var-1, of the main article. But there, red had earlier committed the piece (on 9) to 13. Here, with the piece still on 9, red will crown 3 kings against the bridge. Cont. 14-18, 22-17 and 9-14*, 17-13 (sooner or later. 16-11 no better) 14-17, 16-11, 18-22, 26-23, 22-26, 23-18, 15-22, 30-23, 22-26, 11-7, 26-31, 7-2, 31-27, 23-19, etc. RW.

4A. 28-24,-4B, 7-11*, 26-22, 11-18, 22-15, 2-7, 15-10, (25-22, 7-10 RW) 8-11, 25-22, 14-17.RW.

4B. 15-10, 8-11, 25-22, 11-15, 27-24, 5-9, 20-16, 9-13, 10-6!, 1-10, 24-20, 15-24, 28-19, 3-8*, 22-18, 8-11, 18-9, 11-15, 9-5, 15-24, 5-1, etc. Red wins a long ending.

5. 32-27, 9-14*, 27-24, ( 15-10, 8-11, 27-24, 11-15, 20-16, 15-18, 24-20, 18-27, 31-24, 5-9, 19-15, 12-19, 10-6!, 1-10, 19-15, 9-13 etc. RW) 7-11*, 15-10, 11-15, 20-16, 19-15!, 12-26, 31-13, 2-6, (to stop 24-19) 24-20, 8-12. RW.

To prevent this 1st option Red has (6-9!) I thought 32-27 would draw, as it does stop 6-9, because of the 19-16 3x3 threat.
But checkers is a game of neatness, and tempo, with critical positions, such as this one, requiring proper timing in nearly all cases. 32-27, when you stop and think about it, loses time, to prepare the 24-20 and 28-24 lineup, and that is always dangerous in critical games and positions.

32-27 Line.

32-27, 5-9, 31-26, (best try. If 24-20, 9-13, A ( 17-21 is a longer win,-see note-A) 31-26,
( 27-24, 7-11* is again the win in Note-DD of main article) white is now only 1 move from attaining "the landing" if Red would cooperate with 6-9? then 27-24* would be into the desired landing shown in the main article. But again Red has the winning 7-11*, 28-24, ( 25-21, 11-18, 21-14, 17-22 etc. is hopeless for white) 11-18, 23-14, 8-11, 27-23, 6-10, 14-7, 3-10, 25-21, ( 25-22, 1-5, 23-18 10-14) 17-22, 26-17, 13-22, 23-18, 1-5, 21-17, ( 18-14, 10-17, 21-14, 2-7) 5-9, 17-14, 10-17, 19-15, 9-14 etc. RW.) 17-21, (or 9-13 1st) 25-22, (or 24-20 plays the same) 9-13*, 24-20, is into Note-A.

* A. 17-21, 25-22, ( or 24-20 9-13* same) 9-13, ( 9-14 allows 15-10) 24-20, 7-11*!, (white is 1 move out from attaining the compilation landing. But this deadly move always-threatens! 22-18, 1-5*, ( 2-7 is strong too) 19-16, ( 27-24, 2-7, 19-16x, 7-10 etc. RW) 12-19, 23-7, 3-19, 18-15, ( a fine attempt at a man down draw, that comes up just short!) 5-9*, 20-16, 8-12, 16-11, 9-14, 11-8, 14-18, 15-11, (to stop 13-17) 18-22, 26-17, 13-22, 8-3, and 6-10!, 3-7, 10-14, 7-10, 14-18, 27-24, 19-23. Diagram.


From the diagram:
10-15-A, 23-27, 24-20-B, 27-31*!, ( 27-32?, 11-8, 18-23, 20-16x Dr) 30-26, 22-25*!, 15-29, 31-22, 28-24, ( 11-8, 22-18, 8-3 or 28-24, 18-15 followed by 2-6 RW) 21-25, 11-8, 25-30, 8-3, 30-26, 24-19, 22-18. RW.

A. 10-14, 22-26, 24-19, (nothing better) 26-31, 19-15, 18-22!, ( 12-16?, 11-7*, 2-11, 15-8, 18-22, 14-18, 31-27, 18-25, 23-26, 30-23, 21-30, 23-18 DR.) 14-18, 23-26, 18-25, 31-27, 30-23, 21-30*. RW.
B. 11-8, 18-23*!, ( 27-31?, 30-26, 22-25 etc allows a dr.) 24-20, (nothing better) 27-31*!, 15-18, 23-26, 18-25, 31-27, 30-23, 21-30*, 23-19, 30-26, 8-3-C-D, 27-24, 19-15, 24-19, 15-11, 26-23, 11-8, 2-7!, 3-10, 12-16, etc. RW C. 19-15, 26-23, 8-3, ( 8-4, 12-16 etc) 23-19, 15-11, 27-23, 11-8, 2-7 same as B. D. 8-4, 2-7*, 4-8, 7-10, 8-11, 27-24, 11-7, 24-15, 7-14, 26-23, 14-9, 23-27, 9-14, 27-32, 14-9, 15-11, 9-14, 12-16, etc. Red will hold 2 with 1. Classic Win.


From top diagram, instead of the 32-27 line, white can try 31-26. It does not stop the deadly 6-9 attack, but it makes it a weak variation white can draw. If 31-26, 6-9??, 25-22*!, 9-13, ( 17-21, 22-17*!, 9-13, 26-22, 7-11, 23-18, 11-16, 15-11*, 8-15, 19-10, and everything is inferior for Red. If 16-20, 24-19, 20-24, 17-14, 12-16!, 19-12, 2-6, 28-19, 6-24, 18-15 and red is in trouble) NOW 24-20, 5-9, ( if 7-11, 15-10*, 2-7, 30-25*, 7-14, 25-21, 1-6, 22-18, 5-9, 32-27, 12-16, 19-12, 6-10, 23-19 etc. draws) 28-24, 17-21, ( if 9-14 15-11 etc. or 15-10 draw) 32-28 is back on "the landing."

I then turned to 31-26 (after Chinook's 18-15, 4-8*) in hopes it would draw. There is however that "option" thing again. Red has 17-21*! (to keep 5-9 or 6-9 and then 9-13 or 9-14 option open! If 5-9? white can attain "the landing" with 24-20*) After 31-26, 17-21* red has 5-9* against anything-except 24-20, which allows 6-9!. The draw against 5-9, needs shown. So 31-26, 5-9, 24-20*, ( 25-22?, 17-21! Will win, as 22-17 is now no good after 9-13*, and if 24-20, instead of 22-17, then 9-14* wins immediately.) 9-13-VAR-1, 28-24, 17-21, 25-22, 6-9 and 32-28 is "the desired landing."
Var-1. Computers tend to rate a material gain, many bonus points and a strong game. 9-14 here, does gain a man, but an inferior line.
9-14, 28-24*, 7-10!, 20-16*, 8-11!, 15-8, 10-15, 19-10, 12-28, 8-4, 6-15, 25-22, 17-21, 23-18*, 14-23, 26-10, 2-6, and the beautiful 4-8*!, 3-12, 10-7 to certain draw. Red is now the one who better find a draw, with 12-16 and continue the piece to pitch the man off 30.

While this 31-26, 1st, (instead of 24-20) may draw, the CORRECT DRAW, is 24-20*, against this 4-8.


THE DRAW ON CHINOOK'S 18-15, and 4-8 attack.
(The "15-10 and 22-18 line.")

18-15, 4-8!, 24-20*, ( This is the "clear" way. 31-26 may be ok, then 17-21, and 24-20*, 6-9!, and 25-22* is trunk) 6-9! NOW 31-26*, (SEEKING THE "LANDING" IN A DELAYED WAY) 17-21, and 25-22*!, 9-13, 32-27*. White is only 1 move from attaining the landing, and 5-9 would allow it after 27-24*.

So Red must strike with 7-11, to prevent it.

On 7-11, 15-10*!, ( 22-18 loses, shown earlier in 32-27 line) 2-7, 22-18*, (Corrects #3, line1, 4th move from end, where 19-16? loses) 7-14, 18-9, 5-14, 19-16*, 12-19, 23-16, 23-7, 3-10. Here we must pause. Computers will not play into this. Why? Because the "material loss", (white is a man down) plus a king, (red will crown a king on 29) causes a strong rating, and they avoid it. The upcoming Red king, is however crowning in the weak single corner, and the rest of red's pieces are on the side of the board. Thus, if white is in time to keep the king from "getting out", then it draws, as Red will have to return the piece. From the beginning, ALL the lines available to White, that draw, are by going a man down, to force Red to crown in the weak single corner! (With the lone exception of the bridge on the main page.)

After 3-10, 20-16*, 8-12, 16-11, 14-18, ( or 14-17) 11-7, 18-22, 26-17, 13-22, 7-2, 10-14,
( 22-25, 2-7, 10-14, 7-10, 14-17, 10-15 etc. contains the king) 2-7, 12-16, 7-10, 14-17, 10-15, 22-25, 27-23, 25-29, 15-19, 16-20, 19-15, 29-25, 23-18, 25-22, 18-14 and the king is contained, and cannot get out. Red can allow a stalemate, or return the piece. DRAWN.


So "Chinook's 18-15 does draw. On a first try basis, when asked about this opening, and without a doubt, not making a deep search, and an exhaustive study, the move was sent to Brian Hinkle, resulting in this opening being approved for mail play.

Well "Chinook" is right. The 18-15 move is absolutely necessary to draw this opening.

However is it forced?

As is so often the case, one needs to first examine the original documents n this opening and this 26-19 jump. That is-Walter Hellman's win, published in Midwest Checkers, in April, 1980.
So: 11-16, 23-19, 16-23, 26-19*, 8-11, 27-23*, 11-15, (Hellman tried 4-8 in the Feb. issue of mentioned source, and showed it to draw) 22-18*, 15-22, 25-18, 9-13. 29-25*, 13-17, 21-14, 10-17, forming the critical position.

Hellman showed only 31-26, and attacked this, to a win?, with 5-9, (mentioning this "as better than the 12-16 shot"-see below for play on this) 25-22?, (the question mark is mine) 17-21, 32-27, 4-8, and here showed wins against 19-15 or 24-20. If 18-15?, 9-13* would be into our wins, shown above.

On his 24-20, 8-11, 27-24, ( 19-15, 3-8, 22-17, 9-13, 26-22, 21-25! wins) and 3-8*! is a most important win, that must be considered, and avoided, if we are to draw. Hereafter we will refer to this as the 8-11-3-8 win.


THE DRAW ON HELLMAN'S 31-26 AND 5-9 ATTACK.

* But Hellman's 5-9 attack (all he showed) allows Chinook's 18-15*! (overlooked completely by Hellman)
If we examine what has happened, Red has not gained the tempo with 4-8 threatening those 7-11 wins, and in fact 4-8 (instead of Hellman's 5-9) would allow an alternate draw with 25-22, 17-21 and 22-17, , probably continuing, 8-11, 24-20, 6-10, 28-24 (key move) 5-9, 17-13, 2-6, 26-22, 10-14, 19-15, 14-17, 15-8, 17-26, 23-19, 26-31, 8-4, 7-10, 4-8, 10-14, 18-15, 9-14, 15-10 etc. clears ok. Dr.

In addition, on this 4-8, white can attain "the landing" necessary to draw the opening, without the 25-22 alternate draw, with 24-20, 6-9, (If 17-21,-A, 28-24*, 5-9, 32-28, (prevents Hellman's 8-11 and 3-8 win) 9-13, 25-22 is the landing again. And if 17-21, 28-24*, 6-9, then 25-22, 9-13 32-28 is also the landing. ) 28-24, 17-21, 25-22, 9-13, 32-28*, 5-9, and finally 18-15* forms the compilation landing.

A. 5-9, 18-15*!, 4-8, 9-13, 28-24, 7-11, is shown at top-right column, under diagram-2, in note-A.

If Red tries 6-9, (instead of Hellman's 5-9, or 4-8) both 25-21 and 25-22 are plausible, but if "the landing" is desired, then 24-20, 9-13, 25-22, 4-8, 28-24, (NOT 18-15? Yet, 7-11 would win, and Hellman's 8-11 and 3-8 is not on the board with 6-9 played) 5-9, (to stop a plausible 18-14?) Now Chinook's 18-15, 17-21, ( 9-14, 15-11 or 15-10) 32-28 is the landing.
Back to main page for drawing the landing.

ON THE 31-26 and the 12-16 shot.

31-26, 12-16, 19-12, 3-8, 12-3, 17-21, 3-10, 6-31, 23-19, 31-26, 30-23, 21-30, 19-16, 30-25-A, 16-11, 25-22, 23-19, 22-18, 32-27, 18-14, 19-16, 14-10, 24-20, 5-9, 16-12, 9-14, 12-8, 14-18, 8-3, 18-22, 3-8, 22-26, (there is a threat here with 2-7!, 11-2, 4-11, 2-6 and 10-7!, 6-9, 22-26, and red has 1-6 and 6-10 coming!) 8-12, 26-30, 12-16, (and Red must get out of the "backshot" 11-8 threatens) 10-6, 11-7 Drawn. There is a lot of lay here, not covered, and the results of this 12-16 shot remains unclear. The safe way is Chinook's 18-15*.

A. 5-9, 32-27!, 9-14, 24-20, 30-26, 23-19, 14-18, 27-24, 18-23, 19-15, 23-27, 15-10, 27-31, 10-7, 2-11, 16-7, 31-27, 7-2, 26-22, 24-19, 22-18, 19-16, 18-15, 2-7, 27-23, 16-12, 1-5, ( 23-18 7-11, and 15-19 20-16) 28-24, 5-9 or 23-18, 7-11 etc. Drawn. So "The landing" draws if Red's play forces it. Or if the 7-11 line given above is used to prevent it, then white can still draw the 15-10* line.


We are indebted to "Chinook" for the unwavering support given our game, and furnishing play when requested.


* There is one more point. concerning the "wins" against Chinook's 18-15.

I found a line which has not been resolved!!
The controversial line comes from Chinook's 18-15, 4-8*, 24-20, 6-9*. 31-26, 17-21*, 25-22, 9-13* , 22-18, ( Note-3A, from above. But 15-10* is correct-"the 15-10-22-18 line, shown above) 7-11*, 15-10, 2-7, 18-14, 13-17*. Now instead of 19-16 shown in Note-3A, White can try 10-6!, 1-10, 23-18, forcing 12-16!, 19-12, 10-15, then 26-23, 15-22, 23-19, 22-25, 19-16, 25-29 and 14-10, 7-14, 16-7, 3-10, 12-3 leaving a man down ending (for white) that is unresolved, as to it's outcome.
This apparently is even out of "Chinook's databases, with most opinions being: "You can play it 20 times and win, and the play it 20 more times and find draws!"
I believe Red has to come 29-25 if it will win. Then these points.

1. 3-7?, 25-22, 20-16, 22-18, 16-11, 17-22, 11-8, 22-25, 8-3, 25-29, 7-2. 10-15 loses time FOR WHITE, compared to:

2. 29-25, 20-16, 25-22, 16-11, 10-15! and threaten 15-19-19-23-22-18 and the 23-27 trade to break White's bridge, may win this.




The above analysis on this opening has been analyzed by your truly-AL Lyman- and shown to Brian Hinkle and Dennis Cayton, a few months ago. Others may have found part, or all of it independently.

Since Dennis Cayton is planning a new edition of his "Barred Opening" compilation, I have shared this play with Brian Hinkle, and Dennis Cayton. 6-28-1997.


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