I put the code not only in green, but I also made it bold. And I thought I was exaggerating. No doubt is possible.

Yes but i thought that yogi simply messed up the position before posting.

Taking bout the back game position: isn't hitting two a little dangerous? Oppo can potentially set up a three point backgame. Is hitting one and advance a straggler that bad?

Assuming the position is correct as posted:

Black will be trailing by 23 pips after he plays this 53. That means he can expect a cube that he will be required to pass as soon as contact is broken. His plan, therefore, should be to maximize contact by leaving his two outside blots where they are. White will be loathe to hit unless he can clean up all his blots first.

53 is not a bad number for Black, allowing him to roll his prime forward.

9/4, 7/4

Mike

Man, I'm on a roll. I also played 9/4 7/4.

Again, not entirely sure I would have played that OTB, but this thread has been helpful in getting a more structured thought process going before moving.

You guys are all so very good, that you could come up with an analysis.
Why should black play 9/4 7/4?
White will not hit without being able to cover his 4-point blot or moving that blot to cover his 1-point, that is, when he doesn't throw a 2 or 3, with 22 and 33 being jokers. (Exceptions: with 44 he will hit and make his 3-point, leaving the 2 blots in his homeboard; with 34 he will avoid to leave too many blots, and 21,26,31 don't hit). That means that in about 2/3 of the cases white will not hit, and black's position will have greatly improved if he throws a 1 or 43. So in about 25% of the cases black will be able to luxuriously wait for white to break up one of his points. If black doesn't throw that 1, white will in most cases have some 4-point board with a blot, and black being still not without chances. In the 1/3 of the cases that white will hit, mostly there is the blot on white's 1-point and the opportunity of a double shot in the outerboard if black happens to enter. And if black hits, white will be in dire straits.

Having another fresh look, I see that 65 hits and covers, and am not sure about 11. And 22 is no real joker.

Scrutinizing is allowed.

OK, here's a quick analysis:

Black is now trailing by 31 pips, and he'll trail by 23 after he moves his 5-3. So contact is good for him.

White has two blots in his board, so he has to be very careful about hitting and leaving a shot.

9/4 7/4 builds a 5-point prime, so White has to be even more careful about hitting.

So I'm making the 4-point, and then let's see what White can do.

Black to Play 3-2
XGID=---a--EaC---dE-Aac-e-----A:0:0:1:32:0:0:0:0:10
White - Pips 155

Black - Pips 159

Like beauty, “obvious” may be in the eye of the beholder.

Mike

I am a proponent of hitting as much as possible if the opponent has no board, unless it is unreasonable. See my thread how to create complexity.

What's wrong about B/23 6/3* ?

making the 4pt is very strong when the 5 & 6 are made.

having said that, i over looked it, and missed the correct play. now its clear as can be, so obvious i cant stand it i should have never missed this one, it aint that difficult of a play

I can't see another reasonable option: B/23 6/3. There seems little risk in being hit.

Black to Play 3-2
XGID=---a--EaC---dE-Aac-e-----A:0:0:1:32:0:0:0:0:10
White - Pips 155

Black - Pips 159

The readers nailed this one. There are more opportunities to hit loose on the 3pt in the early game than most players realize. This is one of them. The 3pt is a bit deeper than most loose hits in the inner board (excepting, of course, tempo hits on the ace point). In this position, however, there are several factors in its favor.

• Hitting disconnects White’s runners, making it harder for him to anchor on the bar point.
  
  
• Barring doublets, hitting prevents White from making an offensive point. White has a builder on the 9pt that works well with his spares on the 6pt, 8pt, and 13pt. Left alone, there are many rolls that White can use to make a key point (4pt, 5pt, or 7pt) in his prime field. Many other rolls make the 3pt or 9pt.
  
  
• 3 is duped, so the risk of leaving direct shots at two blots is not as high as it might be otherwise.

My 7k XG2 rollout has hitting (bar/23, 6/3*) ahead of running (bar/22, 15/13) by 31 millipoints of equity. That’s 0.031.

Other examples where it is correct to hit loose on the 3pt include these 2nd-roll plays:

• 52-split, 64-hit (13/3*)
• 52-split, 43-hit (13/9, 6/3*)
• 52-split, 32-hit (13/11, 6/3*, hit-and-split is almost as good)

And these 3rd-roll plays:

• 21-slot, 32-reverse-split (24/22, 13/10), 31-inside (6/5, 6/3*)
• 31-point, 52-split, 21-hit (6/3*)

Mike

I'm not sure if this position belongs here, but I certainly got it wrong. In fact my initial thought on getting the roll was, aha, an obvious move for a change!

I wanted to tell all members that it is okay to post a problem here, but please number it and put a code with it. And the problem should also be at least for intermediates. This problem is really for beginners.

Black to Play 1-1
XGID=-b-B-BCAB-A-cB--ab-eb-A-A-:1:-1:1:11:0:0:0:0:10
White - Pips 152

Black - Pips 139

This is the same position Bleep posted above.

I guess the obvious move that first leaps out is to grab a high anchor on the 21pt. A bit of reflection, however, shows that Black is too strong to just play defense. He should settle for the inferior 22pt anchor so that he can also play some offense. The third ace should be used to make the bar point. The tough part, then, is deciding how to play the final ace.

Black could leave the 8pt slotted, hoping either to make the 8pt or use the checker there as a builder. But his real target is the 4pt. Since he will usually want to keep the bar point, a builder there is just as good for making the 4pt as it would be on the 8pt. Lifting the blot from the 8pt also eliminates 61 and 43 as hitting numbers for White.

Furthermore, if Black leaves a blot on the 8pt, then he will most likely play his final ace moving the blot on the 10pt down to the 9pt. But a builder on the 10pt is ideally situated, exactly 6 pips away from the 4pt Black needs to make. If he cannot make the 4pt next turn, he may be able to cover the 10pt instead.

24/22, 8/7(2)

Mike

Position ID: YDuWAEc72wMABQ Match ID: cIkEAAAAEAAE

I would probably play 6 to 5, 6 to 4, 2 to 1 so I don't leave myself unplayable 6's, by making the 20 point.

Making the 20pt would be an error here. Black needs to jump into the outfield as soon as possible. Making the 20pt would elimintate 6 as an escaping number. By keeping the back checkers split, Black also increases the odds that he will hit a fly shot next turn.

Three of these aces are practically forced, so start by playing 6/5 6/4. Next, decide whether 5/4 is better than 2/1 for the last one. I don’t think it is. I have not checked every roll, but it looks like Black is slightly more flexible with a checker on the 5pt. I doubt much equity is involved.

6/5, 6/4, 2/1

Mike

PS From now on I will wait until 1 day after the rollout post, and if no one has posted a problem, I will do so.

Black to Play 3-1
XGID=-BBDB-B--a-A----B-bbcab-d-:1:1:1:31:0:0:0:0:10
White - Pips 71

Black - Pips 81

As usual, what and why?

Mike

Because of the QF I think 16/15 11/8. After the move black will be 6 behind, which will actually be 9, because those two hind checkers have to do two crossovers. Only 61, 63, 66 and 33 (16%) let white hit and cover, and with the other 6's white will not be hitting. But the chance of losing a gammon is small, because white will have to get two checkers for some probability of this to happen. With 52 and 43 he would rather not hit, but has to. So for white the numbers smaller than 6: 11, 21, 31, 41, 23 (25%) are bad, and 6 or 7: 15,24,25, 34 (25%) are pretty mediocre (and with more likelihood resulting in a gammon if black hits back). So the merits of this play are obviously greater than the demerits.

We do have an obvious play, 11/7. Since, according to the heading, that is "not always right," there is a heavy aroma of quiz factor here! A large percentage of players, including me, will miss this OTB.

I will post the solution later today.

Mike

I thought the same as yogiman, but I doubt I'd make that play over the board. Maybe we should mix in some obvious plays into this thread?

I would have played 10/7 22/21 over the board. Somehow, I thought the 8-pt was still important, creating a boken 6-prime (including a 4-prime in the back).