Bill Robertie

Hit Loose or Split in the Opening

Nov 16, 2021 | Backgammon Problems: Early Game, Uncategorized

Cash game, center cube. White on roll.

White to play 3-1.

Here’s the same position from the last blog post, but this time White has a different roll to play: 3-1.

Here the choice is a little different from before. The only available hit, Bar/24 6/3*, is now a horrible blunder. It has all the disadvantages of the hits in the last post, but in addition it leaves White stuck on the 24-point, just when White needs to be taking some small risks to get an advanced anchor in Black’s board.

Instead, White needs to enter with the three, Bar/22, which gives him both an escaping number (6) and a threat to make an anchor, and then consider whether 24/23 or 22/21 is his best ace. The former is a little safer since White avoids moving to the point Black most wants to make next (Black’s 4-point). The latter play moves directly to that point, hoping to later grab the best anchor available.

Either play might be right depending on circumstances. Here the circumstances favor moving to the 21-point. To see why, we’ll use a frequently handy trick in these sorts of positions. Find Black’s best non-double that attacks or advances his prime, and see how that number plays on the other side of the board. The right play will often duplicate this number.

After Bar/22/21, Black’s best non-double for advancing his prime is clearly 4-2, which plays 8/4* 6/4. But on the other side of the board, 4-2 is also a great shot, making the 20-point anchor. Eureka — duplication!

Now consider Bar/22 24/23. Black’s best non-double for moving his prime is 5-3, which he would play 8/3* 5/3. But on the other side of the board, 5-3 is pretty useless. Hence the 24/23 play creates a new great number for Black, which isn’t the right idea. So White should just play the simple Bar/22/21.

Hit Loose or Play Quietly?

Oct 15, 2021 | Backgammon Problems: Early Game

Cash game, center cube. White on roll. White to play 5-3.

Many backgammon problems boil down to a simple question: hit, or don’t hit. In essence, backgammon is a pretty simple game. In general, you want to make points, and in general, you want to hit.

Doubling an Early Position

Oct 1, 2021 | Backgammon Problems: Early Game

Cash game, center cube. White on roll.

(a) Should White double?

(b) If doubled, should Black take, drop, or beaver?

Early game doubles cover a wide variety of positions, but in general they can be spotted by analyzing three key aspects of the game: race, position, and threats. Many years ago, Joe Sylvester (a very great player in the 80s and 90s, now somewhat inactive) coined a simple rule: if you’re ahead in two out of three of these aspects, you have a double. Your opponent may or may not have a take. Let’s evaluate these three features of Problem 12 and see what they tell us.

Playing for a Decisive Advantage

Sep 15, 2021 | Backgammon Problems: Middle Game

Cash game, center cube. Black to play 6-1.

This position is somewhat unusual. We have a roughly balanced middle game in which both sides have moderately strong home boards. Black has only one man back, and as a result White trails in the pip count by 15 pips (136 to 121).

White’s roll, 6-1, is awkward since he has no great six. Moving off the midpoint leaves a shot. Moving off the 24-point creates two blots and breaks his defensive anchor. The only sensible play that involves moving from the 7-point or 8-point is the loose hit, 8/1*, which doesn’t accomplish much. Nonetheless, White does have to pick one choice from this unappetizing situation.

Playing Blocking Games

Sep 1, 2021 | Backgammon Problems: Middle Game

Cash game, center cube, White on roll.

Part (a): White to play 4-3.

Part (b): White to play 5-1.

Both sides have anchors on the opposing 3-points, and both sides have established a few points in front of the enemy anchor. I like to call these ‘Block versus Block’ positions, to distinguish them from the better-known ‘Prime versus Prime’ positions.

Three Interesting Problems

Aug 15, 2021 | Backgammon Problems: Middle Game

Here are three problems the early stages of a long match. Try your hand and see how you do.

(A) Match, score 0-0 to 17, center cube.

White to play 3-1.

(B) Match, White leads 1-0 to 17, center cube.

White to play 5-4.

(C) Match, White leads 1-0 to 17, center cube.

Should White double? Should Black take if doubled?

Position (A): This one should have been pretty easy. When you have a 5-prime with a checker trapped behind it and not at the edge, your game plan is to make a 6-prime, and the easiest way to do that is usually to slot the prime from the back, with the idea of covering next turn. White should therefore see this as a pretty good roll and just play 13/9. The play has the added bonus of duplicating Black’s aces, since he now needs ones to hit and ones to get to the edge of the prime.

Hitting with 6/2* is a major blunder. White needs the 3-point or the 9-point to complete a 6-prime, and he only has three checkers that can participate in that fight. Playing 6/2* effectively burns one of those checkers, since the 2-point has no importance yet and White has no need for a tempo hit.

Position (B): A 6-6 on the second roll of the game is usually a great shot, giving White a lead in the race plus a couple of good points. The follow-up, however, can be tricky. With a 5-4 on the next turn, the best play is usually breaking off the anchor with 18/13/18/14. When White doesn’t get hit, he’s got plenty of builders and spares and a good chance of capitalizing on his racing lead.

Attacking with 8/3* 7/3 looks appealing at first glance, but it’s not as strong as you might think. Black has 12 immediate hits (52, 56, 43, 46, 26 and 16) that catch up in the race, plus 5-4 as a great anchoring number. Even when Black doesn’t immediately hit, the game frequently evolves into a holding game where White wants to get off his anchor on the 18-point but can’t.

Position (C): This position is tricky over the board because the solution depends on just how you ‘see’ the situation. If you see this as just a blitz, then it’s clearly not a double. White doesn’t even have a checker in the air and Black just has a 2-point board.

But if you see this through the lens of Joe Sylvester’s Position-Race-Threat matrix, then it looks very different. White leads in the race by 25 pips, 134-159. His position is better, with an extra inner point on his side and a strong anchor on Black’s side. White has threats, with a bunch of numbers to make the 4-point and other numbers that put two checkers in the air. His position is better and it’s threatening to get better still, maybe by a lot. Looked at this way, it’s an easy double and Black has the tough decision. He can take because so far he’s only facing a 2-point board and the threats are not crushing.