Whats the right play here and why? Is there any generalized rule or advice for helping make the right play here?

What a great position! Do remember the move sequence that led to this? If so, kindly post it so I can add it to my collection of early game sequences.

I like this position because the choice is clearly presented. Black can make a five-point board, but give his opponent 11 chances to anchor, or else Black can hit a second checker, while completing only a four-point board. Hitting a second checker reduces the chance of his opponent anchoring to only 2 rolls.

Both options do two good things. The first makes two new points. The second makes only one new point, but also hits.

Usually the best advice in a blitz is that quantity, not quality, of points is what matters. With two up, and plenty of wood available for attack, making the 2pt or 1pt is just as good as making the 4pt or 5pt.

Notice the caveat. If Black makes his 2pt here, he will be left with only two spares in the zone, and both of them will be on the same point. When White enters a checker, Black will be an underdog to hit it. If White eventually anchors, Black will be left with four checkers holding down the 1pt and 2pt that cannot be part of a prime. In this position, Black does not have "plenty of wood" to use in an attack.

For that reason, my over-the-board play would be to make up the five-point board, and then see what happens. No matter whether White anchors or not, I would be in the drivers seat.

Late addition: One well-played sequence that leads to this position is the one that follows. I am using Nack Ballard's arbitrary definition that well-played means that all plays are within 0.02 of best. For White's 42, there are several good alternatives, but the one in this sequence edged into first place in a short XGR++-like truncated rollout.

White: 63-split – 24/18, 13/10
Black: 61-point – 13/7, 8/7

White: 42-both up and down – bar/21, 10/8
Black: 55-attack – 8/3*(2), 6/1*(2)

White: fan
Black: Double

White: Take
Black: 52-hit: 13/8, 6/4*

White: 62-forced – bar/23
Black: 22 ?

I'm not sure whether this is the one you played, but at least it gets you there.

Mike

I like Mike's analysis. Although pointing on White's head for a 2nd checker on the bar seems rewarding, locking up the 5-pt board looks stronger, more flexible.

I think Mike hit the nail on the head with this one and I learned something very valuable from it. Just because we have 10 checkers in the zone does not mean that our blitzing plan includes keeping 2 on the roof at all costs. Looking at the flexibility of said checkers in the zone is important, along with where the opponent has a chance to anchor up.

Yeah, the 5 point board seems right. Here's the other thing to notice: It's not like white is going to be able to move around comfortably. Look at all the possible entering rolls:

21 - You get a direct shot from your back anchor.
22 - He makes the 4 point and leaves you an indirect shot (I'm pretty sure 13/11 is the last 2).
23 - He leaves you an indirect shot from your back anchor.
24 - He leaves you an indirect shot from your back anchor.
25 - He either enters and plays 13/8 to make ugly stacks, or he leaves you a direct shot from your midpoint.
26 - You're getting a direct shot.

So even if he enters, it's not like he's going to be happy with things.

If I can express an opinion:

I think that positions like this one are very interesting but pratically the difference between the first and the second move are too much close to define one a blunder or even an error.

Here I would have blitzed putting opponent with two on the roof, and I still think that one has to be more inclined to do so instead of the positional one.

It's very tempting

but it's also true that if you don't hit opponent may anchor and white's position, althoug difficult, has some hope due to somewhat good white timing. Put it another way: if black blitz white has to re-enter with one AND anchor with the second AND not being hit meanwhile, if black doesn't hit white has only to anchor and gammon chances rapidly vanish

True: black's ammo is low but not completely out. Black blitzes, white fans either with one or two and black add ammo from the midpoint or maybe hit and if white hasn't anchored he/she will likely lose a gammon.

I think that here the most distractions come from the fact that the positional play is more aesthetical and stuck white behind a 5 prime with two checkers but since black lacks spares I think white is not completely dead and I think that losing that gammon potential is a real waste

Mike, if I can ask - what do you do with this collection of games, and how does it help you?

FWIW, I would have played 8/2 4/2

I would play 8/4 7/5(2) on the grounds that 1. it can still lead to a closeout - this is a 5 point board after all; and 2. if opponent does anchor I retain a much better game than if he anchors after making the 2 point.

I wonder which is right.

Your's is not bad advice. The problem with going against normal principles of play is that when you are wrong, you will often be wrong by a lot. The standard play in a blitz is to keep hitting, and that should be the first thing you look at here. On the other hand, if you are experienced enough to be able to discriminate between the standard plays and the exceptions, it certainly is correct to do so.

One of the things that makes this position an exception is that Black is a huge favorite after he makes up his board. Owning a five-point board at a time when your opponent has a checker on the roof and has not made a single new point since the start of the game translates into many victories (and many gammons) no matter how the rest of the game goes.

Leaving a double-gap on the 4pt and 5pt (while six checkers are tied up holding down the 1pt, 2pt and 3pt) leaves your opponent many more opportunities to turn the game around.

Mike

I have a spreadsheet that uses Nactation and nacbracs to summarize rollouts and XGR++ evaluations for almost 3000 early game positions.

For instance, the move sequence for the position in this thread is:

63S-61P-42b-55A-F-C-52H-2-22

The letters above are the same letters I gave in the more lengthy sequence of my earlier post:

White: 63S = 63-split – 24/18, 13/10
Black: 61P = 61-point – 13/7, 8/7

White: 42b = 42-both up and down – bar/21, 10/8
Black: 55A = 55-attack – 8/3*(2), 6/1*(2)

White: F = Fan
Black: C = Initial cube (and take)

White: Take
Black: 52H = 52-hit: 13/8, 6/4*

White: 2 = 62-forced – bar/23
Black: 22 ?

You will see a lot of Nactation in the forums at bgonline.org. I try to stay away from it here, because Bill thinks it just confuses the beginners and intermediates who frequent TwoPlusTwo. (He has a point!) On the other hand, if you are recording data from a large number of rollouts, there is probably no better method. I tried to make that case in a post last year at BGO that explains why I like Nactation. Incidentally, that post also contains some interesting data for the second-roll position 21$-62 (i.e., 21-slot, 62).

If you (or any other reader) is interested, send me a PM with your email address, and I will send you a copy of my spreadsheet.

Mike

Thanks for the explanation - pm coming.

Cheers.

Look at this very similar position I came across today.

Do we have 2 extra gammons for each extra loss when we play 5/3* (2) 4/2* (2) instead of 7/3* (2)? Maybe the 3rd checker on the bar swings it in favor of the double switch/hit, but I'm not sure at all...

I think I still prefer a 5-pt board, because there's a blot on the 12-pt that will very likely be picked anyway.

Interesting position. especially with the GF. OTB i play 7/3*(2) without thinking much about it. with the QF i see the 5/3*(2) 4/2*(2) play and i really look valuable: it will prevent the opponent to anchor. does it worth giving away the 5 point board.... tough...

i looked long and hard but i think that with so little checker in the area to make the 5 or 4 point it does not worth it, just get the 5 point board.

If XG disagree with me, no biggy, i used to that (damn child of mine)