Problem of the Week #33: October 18


Cash game. Center cube. Black on move.




(a) Black to play 5-4.




(b) Black to play 6-2.

(a) Although we have a 15 pip lead and would like to make a safe play, we don't want it to be inflexible. Therefore 8/3 is out. Same thing for the loose hit 6/1* because we have no good 4 anyway to support it. That leaves us with either 16/11 or 13/8. After 13/8 (unstacks the midpoint, put a 2nd spare on the 8-point), we can play 8/4, 6/2 (both slotting the home board against contact) and 13/9. Of the 2 slotting plays, 8/4 is obviously better. But what about 13/9? I think I would prefer this one, because we lose less pips if we are hit and it forces White to leave his anchor.

Now, what about playing 16/11 instead? That gives us 2 more candidates with either 13/9 or 8/4. For the same reason than above, I'd prefer 13/9. So what's better, 13/8 13/9 or 16/11 13/9 ? They both leave the same number of shots, but I prefer 16/11 13/9, because almost all shots force White to leave the anchor. After 13/8 13/9, White can hit on the 16-point while leaving his midpoint without great danger because he has Black's bar point.


(b) The race pretty even (Black is 2 pip behind before the roll). 13/7 9/7 seems obvious (also duplicates 1s), but it costs the midpoint. Is it worth it? 16/8 leaves 6 less shots and keeps the midpoint. 9/1 leaves no shot but wastes a checker in a holding game, so I discard that one. Blockades are important in a holding game, but keeping the checkers connected (midpoint) also. Which is more important here? I say we keep the midpoint. (Plus we add a spare on the 8-point that might prove very useful.)

(a) 16/11 13/9
(b) 16/8

a) Reject 6/1* because even if it made sense otherwise, you'd have to leave a third blot somewhere.

You have to leave two blots so put them where they will do the most good and/or make Villain leave a valuable point to hit.

16/11 13/9.

b) Choice is between 16/8 and 13/7 9/7. I'd love to make the bar-point but it just looks too risky. Things could go south in a hurry and the 4-prime isn't really enough to slow down Villain in that case. Instead, keep things safer with 16/8, and if Villain whiffs on the shot he's not gonna be real happy with his position.

16/8.

a) That's a pretty ugly roll. Not much duplication is possible. Let's count the shots.

6/1* 13/9 (all aces (11)+22,42,44,54,52): 19 shots.
16/11 6/2 (all aces and fours (20)+22): 21 shots
16/11 8/4 (all threes and fours (20)+22+21): 23 shots
16/11 13/9 (all twos and fours (20)+31+53): 24 shots
13/8 13/9 (all twos and fours (20)+31+53+63): 26 shots

Not getting hit here seems pretty important, so I don't think, that forcing white to break his anchor a big enough factor to make up for leaving 3 extra shots to make 16/11 13/9 better than 16/11 6/2.

6/1* 13/9 has the major drawback, that it leaves an extra blot, we put a checker on the ace point and it leaves some cleanup to be done on the next roll. Overall I think that's a little too much to save two shots, so my vote is for 16/11 6/2.

b) I'll take the four prime here. Looks dangerous, but we have an anchor, white has a blot and the fours are duplicated and white would still need to jump three men over our prime. If white fails to roll a six pretty quickly he could easily get in a lot of trouble.

a) 16/11 13/9

Hitting loose on the ace point nets basically no benefit but risks losing a lot pips If he's going to hit me, I want him to give up the bar point. I don't want him to hit me for "free."

b) 13/7 9/7

Since his checkers are stacked on the 4 point, making the bar point means he's going to need a 6 to escape. You also have some of his numbers duplicated (1s hit in two different spots, and 4s cover his ace point but also hits from the midpoint). Also, I want him to give up an asset if he's going to hit (I think that's the theme). If you leave the shot on the 9 point, then a 6 will accomplish two good things at no cost to white. He can free up a checker AND hit without losing his anchor. That's bad for black.

a) 13/8, 13/9 looks best.
White will probably have to break the bar point or the midpoint to get the hit. If you avoid the hits, you should be able to use those checkers on the 6,8 and 9 points to make some valuable points in your home board.
b) 16/8. Nothing else seems to make sense. Making the bar point doesn't look like a good idea.

a) looks like we have to leave two blots. no duplications . i like 16-11 , 13-9, because i prefer been hit by my opponent strongest position, and i only have 3 shots ( 2-2 4-2) for the double hit. if hit my opp have to leave his 7 point which it's not so bad ( since the bad roll we have ).

b)the problem here is the timing and the 5 chekers on our 6 point. thats why i dont like the safer play (16-8) , but i prefer to slot ; i leave some shot, but i this play is much more profitable if the game gets complicated, which is much likely to happen : 16-10 , 6-4
13-7 , 9-7 give us a good prime , but give white the complete domination of the centerfield; we have two ( or more if been hit ) chekers to run with , and its very unlikely to do it without center chekers.

Just a beginner here, but I'll take a shot:

A) I like the 13/9 move, as we need builders. I don't want to waste a move with 13/8, so I make the hit at 5/1. White will have to break 7 or 12 to hit us twice, and we have a good shot at not getting hit at all. 13/9 5/1

B) I'd play this one conservatively, 16/8, and hope white rolls 5-X next turn.

a) 16/11 13/9. Have to leave two shots no matter what, and this move has the advantage of running the back checker and forcing White to break my bar point for most hits. I don't think anything else is very close.

b) 13/7, 9/7. The 4-prime looks too good to be ignored here and with an anchor, White loose in his board, and 1s duplicated, the move isn't quite as dangerous as it looks. And again White will be forced to give up a strong point to hit with the 4.

i may be horribly wrong, but i think the theme is about realising that we should think about taking a risk and considering to move into a back-game if it doesnt pay off.

a) agree with the general thread idea.

b) not going to move my checkers on the 13-point as they are my 'gate' for the ones on the 23-point and also give me some control of the board against his checkers on the 3-point. the checkers on the 23point will come in handy if my gamble doesnt pay off, sooo, definitely playing 16/10.

not liking the fact that my 6point is so stacked, so slotting the 4 points seems pretty good to me right about now. if we get hit, big deal. we can still re-enter 50% of the time and have a chance of sending him to the bar too. his mid-board position is pretty weak so he's not going to be making very many (if any) home board points for a while, so leaving a few shots and potentially getting into a monster position far out-weighs the danger of getting hit a few times and being sent to the bar. playing 6/4

Usually, you don't want to be looking to get into a backgame unless you've got at least three checkers back already and you're pretty far behind in the race.

oops.

im learning hehe.

In assessing our options, how should we account for white having to play off the bar when we make the hit 6/1*? Intuitively I know that forcing white to play in from the bar is worth some extra risk, but how much?

Blurp....bffft..qwfsdvfaxczxzcvzxczxc.////


Please turnoff your avatar..sadfgzsdf. cannot think clearly.....sdzfvzcxveravgdf.....

on the sadvasd other acvvv33 hand...vasdfg vfxcz don't.

Believe it or not, what *really* gets me about that avatar is her smile.

Problem 33(a)
With his last backman nearly escaped, and a big lead in the race, Black was hoping to safety his blot on this turn. Instead, he finds that he must expose a second blot.

When forced to leave a blot, Black should consider these sometimes conflicting priorities:

• Leaving the fewest number of shots -- Playing 16/11, 6/2 does that here, leaving 21 shots that hit.
• Maximizing the chance of covering/safetying his blots on the next turn -- To this end, 13/4, which leaves a direct cover for the four point, is better than 16/11, 8/4.
• Slotting the most desirable point -- As long Black is forced to leave a blot, he should put it where it belongs. In this case, slotting the four point is clearly better than slotting the one, two, nine or eleven points.
• Slotting from an over-stacked point -- It is often wrong to strip the last builder from a point in order to slot. Black should be looking to advance his trailing checker or move from the thirteen or six points. Stripping the eight point in order to slot is probably a mistake.
• Breaking a point that might be hard to clear later -- In practice, this often means breaking from the rear, something that is not applicable to this position.

In Problem 33(a), Black should realize that his backmen have not completed their escape. There is still plenty of contact, and he may well be hit in the next couple of turns. He should, therefore, play for position rather than safety. Balancing the considerations above, Black should slot his four point.

My solution: 13/4.

Problem 33(b)
In some ways, this position is like a mutual holding game where both sides have a low anchor. Neither player has a strong prime, and timing has gotten tight for both.

A tempting six for Black is to play 16/10. This move gets his blot out from under a double shot, and leaves White only an indirect seven to hit it. For his two, Black might safety that blot, playing 10/8, or slot his bar, 9/7. Between these, the safe play, 10/8, is probably best, leaving only fifteen shots.

A bolder two could be played 6/4, slotting Black's four point. The attraction of this move is that it starts to unstack Black's six point. Black is beginning to be desperate to get the extra checkers there into the game, preferably before he gives up his outfield position. He's playing with only twelve men as things stand. White would hit one of Black's three blots with any one, six or seven, twenty-four shots in all.

Another tempting idea for Black is to make his bar point, 13/7, 9/7. This move pressures White to roll an immediate six or 5-1. Otherwise, White will likely be forced to give up one of his outfield points. The downside here occurs when Black loses outfield control. Note the irony: Black abandons his only outfield point in an attempt to force White off one of his two points in the outfield. Considering that White cannot form a prime that contains both his four and ten points, White may wish to give up his ten point anyway. When Black makes the bar, White gets a double shot to hit twenty-one times in thirty-six.

Nevertheless, the resulting block is strong, and Black's partners should not protest too much if, as captain, he were to make this play in a chouette. A better play, however, is the more positional slot of the four point. It achieves balance in both inner and outer boards at a time when Black should expect that more hits are on the way.

My solution: 16/10, 6/4.

For the Record
I am so often wrong that I like to post my record in these messages. It's kind of a truth-in-advertising thing. I have been answering these problems without the use of a bot, and before checking the excellent solutions of others, since Problem 28. My record at this writing is 66% correct.
Correct: 28(a), 29, 30, 32
Incorrect: 28(b), 31

Note that with your play, you leave 22 shots out of 36.

Help me out with this: I see direct ones and fours for twenty shots, plus indirect fours that don't include a one, i.e, 2-2. As for tens, only 6-4 hits, but we have already counted fours. I'm still getting twenty-one shots.

By the way, in Problem 33(a), mute found a safer play than 16/11, 6/2. It's the horrible hitting move, 13/9, 6/1*. I should have said, "If we discard the hit on Black's one point, then the safest play is 16/11, 6/2."

Since I suggested 13/9 6/1* as my solution (I mis-typed 5/1, but that's what I meant), perhaps you could expand on why that is so horrible?

I'm not crazy about the 6/1* hit, but it seemed the lesser evil to me. As a beginner, I have trouble evaluating the dis-advantage to white that putting him on the bar poses and how to balance this against the other options.

You seem to make a big point that if you make the bar point, White will then have 21 rolls that hit.

I just want to say that with your move (16/10 6/4), there are 22 hit rolls: any 1 or 6 plus 4-3.

- You have no real attacking/closeout prospects
- It puts one of your checkers out of play AND exposed, or two checkers out of play if you decide to cover it later
- Sometimes you have to make this play anyway to try to steal a half roll or full roll, but there's no need for that here. If anything, you'd rather have White moving because he will often have to make a concession of some sort.

You missed the combination 4-2 that hits on the nine point.

Horrible is probably too strong a term! In truth, I'm none too excited about the moves I'm suggesting. As my record shows, I've got a lot to be modest about.

Pineapple888 has said it pretty well. I would add that hitting forces Black to open up a third blot in this position. White would hit with ones, twos and fours, nineteen shots in all. Coming in from the bar, Black would have quite a scramble to safety all his men next time.

If Black gets away with the hit, he's not in such great shape either. He would have no real choice but to cover on the one point. He could do that with fives, sevens, eights, twelves and fifteens: eighteen shots in all. Most of these, however, would leave his blots in the outfield open to attack. Compare this with the move 13/4. After that play, Black could cover on the four point with twos, fours, nines and twelves, twenty-six shots total.

In defense of the hit, you might force White off your one point, and gain a safe landing place for your checkers coming home. Magriel has a section called Force Him Away describing this tactic in his famous tome. You've probably seen this idea used in the bear-off. Here, however, it doesn't really apply. Black would need to roll well, and avoid all hits from his opponent White during the bear-in.

You're right, so that's even worse then: 24 shots hit with your move, compared to 21 when making the bar point. At least with your move, you keep the midpoint.