To Slot or Not to Slot? Chris Bray [email protected].

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To Slot or Not to Slot? Chris Bray [email protected]

Transcript of To Slot or Not to Slot? Chris Bray [email protected].

Page 1: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

To Slot or Not to Slot?

Chris [email protected]

Page 2: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Definition

To slot is to expose a blot to an immediate direct shot with the objective of making a key point on the board.

Page 3: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Contents

General Principles The Opening The Middle Game The End Game

Page 4: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

General Principles

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Reasons for Slotting

To make a point that would be difficult to make ‘naturally’

To unstack heavy points To utilise sparse resources

effectively To reduce a game to a one-roll

proposition

Page 6: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Magriel’s Principles - Tactical

Do you have an advanced anchor? Having an advanced anchor enables you to play boldly.

How strong is your opponent’s home board? The stronger your opponent’s home board, the more conservatively you must play.

How strong is your home board (especially compared to your opponent’s)? If you have more home board points than your opponent, you tend to play boldly; with fewer points closed, more conservatively.

Does your opponent have blots in his home board? If your opponent has blots in his home board, you can afford to take more chances because of possible return shots.

Page 7: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Magriel’s Principles - Strategic

How many checkers do you have back? The more checkers you have back, the more chances you can take. With no checkers back, or only one checker back, you must play conservatively.

How many checkers does your opponent have back? When you opponent has no checkers back or only one checker back, you want to play provocatively to force an exchange of hits.

Page 8: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Other Key General Principles

Put your checkers where you want them

When in doubt, hit Prime an anchor; attack a blot When ahead in the race, race

Page 9: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

The Opening

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The Opening Roll – Black to Play 21, 41 or 51

Correct Play: Your choice!

Page 11: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

In the opening the bots will tell you there is always a best move but it is largely a question of style and what you feel comfortable with so play whatever you prefer.

For the record the bots’ preferences are to slot with 21 and split with 41 or 51.

Certain match scores will dictate whether to slot or split. When trailing you should prefer to slot and when leading to split.

Page 12: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

The First Response

Correct Play: 13/9, 6/5

Page 13: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

Once the opening roll has been made you don’t have so much choice. There is nearly always a ‘best move’ in response.

When you opponent has brought down builders it is nearly always correct to slot with 21, 41 and 51 in response.

The reasons are: It duplicates some your opponent’s numbers It unstacks a heavy point Your opponent now has more checkers in ‘the zone’ so if you split a blitz

attack by your opponent becomes a possibility The equity differences are relatively small but big enough that you

should learn to slot in these situations.

Page 14: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

And slightly later …..

Correct Play: bar/21, 6/5

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Commentary

Here black is further behind in the race. Reject bar/24, 13/9 – an awful move that does virtually nothing to

improve your position The four is played bar/21 The one can be played 6/5 or 24/23 As in the previous position, 6/5 is the correct play

It duplicates some your opponent’s numbers It unstacks a heavy point The anchor on the 24-pt protects against a blitz

Bar/21, 24/23 is a common misplay in this type of position – learn to avoid it.

Page 16: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Opening Summary

Opening roll slot is optional (except in certain match play situations)

The response to the opening roll is not optional

When behind in the race early on slotting becomes more attractive

Page 17: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

The Middle Game

Page 18: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Back in the 1970’s

Correct Play: 24/21, 24/23

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Commentary

This and the next position are from from Barclay Cooke’s ‘Paradoxes and Probabilities’. Of the 168 problems in he book, 44 of them have solutions that are blunders!

In the 1970’s pure play was the order of the day! The trick here is to find the ‘Cooke’ move Cooke suggested 13/10, 6/5 - a move that does nothing to meet the

demands of the position! The front checkers are well positioned – time to get the back men

going with 24/21, 24/23 while white has only eight checkers in the zone and a disjointed position.

Page 20: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Back in the 1970’s (2)

Correct Play: 8/2*/1

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Commentary

Here Cooke’s solution is even worse – 13/7, 5/4. Purity for purity’s sake! This is a huge equity error

We have learnt that once you start the ace-point you should quite often make it.

Here we have a lone back blot and remember – attack a blot. The obvious and correct play is 8/2*/1

Page 22: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Key Points to Consider Check Magriel’s Criteria How strong is your opponent’s home

board Life after death? How is the race? Is your opponent on the bar? How many back checkers does your

opponent have? Where is the cube? Gammon risk?

Page 23: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Simple Start – Slot, Split or Smooth?

Correct Play: 6/5

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Commentary

The race is equal You opponent has the slightly better home board and ten checkers in

the zone. None of the basic criteria suggest slotting. You have a good position that can develop naturally Splitting allows a blitz attack and doesn’t gain enough in return The simple 6/5 is best – awaiting developments

Page 25: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Basic Question – Split or Slot?

Correct Play: 13/8, 6/5

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Commentary

The five is obvious – 13/8. Then slot or split. Normally priming a blot is not the obvious plan but here 6/5 threatens

to create a five-point prime and if not hit give black a strong position. On the other side of the board once more white has 10 men in the

zone and a disjointed position. He would love black to split and give him the chance of a blitz

Once you study 13/8, 6/5 the play looks obvious but that doesn’t mean it’s easy to find over the board.

Page 27: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Is now the time?

Correct Play: 8/2, 8/7

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Commentary

One could try a Cookesque 13/7, 6/5 but that would be a blunder. 7/1, 6/5 is a better slot However none of the basic criteria suggest slotting here. The race and positions are equal and there is no huge gain from

slotting. Time for a quiet waiting play 8/2, 8/7 Not the dreadful 21/14 (duplicating 2’s) as played in the game from

which this position was taken. White rolled 54 and played 13/4*. Black fanned and had to pass white’s double!

Page 29: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

… or now?

Correct Play: 13/7, 13/8

Page 30: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

Here everything cries out for the slot 13/7, 13/8 Black has the better home board. If the slotted point is made black will have a very strong position If white hits, black could end up blitzing him because of all the return shots

and exposed blots (white may not hit with some of his ‘hitting’ numbers (e.g. 51) for precisely this reason)

White has blitzing potential (this is a recurring theme) The building play 13/8, 10/4 does not meet the demand of the position

Page 31: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Slightly more difficult

Correct Play: 15/11, 6/5

Page 32: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

Again all the criteria cry out for a slot: Black needs the 5-pt He is unlikely to make it naturally He is behind in the race He has an anchor Making the 5-pt could lead to a powerful double

The correct play is 15/11, 6/5 Any other move is a blunder or worse 13/9, 6/5 is also a big error! 15/11 provides more covers but I’m still

surprised at the equity difference. Note: The new bot ExtremeGammon prefers 15/11, 8/7 which opens

up a whole new debate

Page 33: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

… and more difficult again

Correct Play: 13/9, 24/23

Page 34: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

This one is slightly surprising as it intuitively looks right to slot with 8/7 However, notice some key points:

The race is close There is no real duplication of white’s numbers While black builds his prime white will be counter-priming

Black does better by splitting 24/23 and attacking white’s blots. The plan may backfire and white run a successful blitz but black’s front position (his 5-pt) will protect him to a certain extent.

It is not a blunder to play 8/7 but it is an error. This is a difficult problem and many would get it wrong over the board. Note that the ‘do nothing’ play with the one – 6/5 – is the wrong idea.

Black should take action on one side of the board or the other

Page 35: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

And really difficult!

Correct Play: 23/18, 15/14!!

Page 36: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

Fantastically difficult position from the 2009 World Championship Final!

The bots have taught us that when your opponent is on the bar you can take a lot of risks with slotting, especially when you have a five-point home board.

Any move other than 23/18, 15/14 is big mistake! Credit to Lars Trabolt for finding the play under the extreme pressure

of a WC final. Sadly his play was not rewarded with a win! Key point – when your opponent is on the bar is the time to take risks This position is a graphic demonstration of that principle

Page 37: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Piano or Forte?

Correct Play: 14/5

Page 38: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

This is an example of turning the game into a one roll proposition Black is crying out for his 5-pt – without it he can’t win the game Black must play 14/5. If white doesn’t hit he must drop black’s redouble next turn By slotting black makes himself a big favourite. Any other play leaves him with a lot of work to do.

Page 39: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Piano or Forte (2)?

Correct Play: 21/16, 11/10 or 21/15

Page 40: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

This one is not so clear The race is closer If black slots and gets hit he could lose a gammon He can get good outfield coverage with either 21/16 or 21/15, 11/10

(note he must ensure he gets hit with white’s 55) When good outfield coverage is possible it is often the right play and

here black must balance aggression against the gammon risk. Coverage wins and one of the quiet plays is correct.

Page 41: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Pick and Pass or Not?

Correct Play: 5/3*/2

Page 42: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

At first glance 5/3*, 11/10 looks obvious but White has a four-point board so when black is hit he will lose a lot of

gammons The race is relatively close Black is approaching a redouble and should not jeopardise that cube turn His checkers are well distributed anyway and the immediate capture of his

3-pt is not essential to winning the game The quiet play: 5/3*/2 is correct by quite some margin

Page 43: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Desperation Stakes?

Correct Play: 8/4, 24/23

Page 44: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

Here black is losing and losing badly Whatever he does he will lose a lot of gammons It will take a miracle to save him To do that he will need his 4-pt as soon as possible To do that he must slot it now with the hope of making it next turn 8/4, 24/23 is the only viable play!

Page 45: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

The End Game

Page 46: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Considerations

How many checkers off? How strong are the home boards? Strength of outfield coverage? Which point requires slotting? Direct cover or not? (rule of thumb is to

have one direct cover before slotting) Where is the cube? How many men on the bar? (never slot

against two on the bar)

Page 47: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Open 6-pt

Correct Play: 14/6

Page 48: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

The 6-pt is often slotted. Lower points less frequently and the 2-pt and 1-pt are virtually never slotted.

The reason is that whenever your opponent enters on the 6-pt he also escapes – that is not true of the lower points.

Here there is an urgency to make the 6-pt in order to win the game Black already has two checkers out of play 14/6 is both thematic and correct.

Page 49: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Open 5-pt

Correct Play: 20/14, 13/11

Page 50: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

Just one point difference but now the slot is wrong! Making the point 6 away from the open point is a recurring theme in

positions like this 20/14, 13/11 provides excellent coverage without the risk of slotting White’s 3-pt board still ensures that black loses some gammons when

he is hit. It’s these gammon losses that swing the solution to 20/14, 13/11

Page 51: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Open 5-pt (2)

Correct Play: 13/5

Page 52: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

Now the situation is more urgent and white has a weaker home board. It’s surprising how weak the opponent’s home board has to be

(normally only two points) before you start taking liberties with slots and trap plays.

This (just) swings the answer to 13/5 but that play and 20/14, 13/11 are nearly equal in equity.

Note: Once again, ExtremeGammon disagrees and prefers 20/14, 13/11.

As Jeremy Bagai says in ‘Classic Backgammon Revisited’: “The pendulum of style continues to swing throughout the modern era, but the arc gets shorter as progress is made.” Maybe, but there’s still some interesting material to be found within that arc!

Page 53: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Open 5-pt (3)

Correct Play: 11/5*/4

Page 54: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

Another situation where black is closing in on a redouble. Now leaving the points slotted is overkill and when things go wrong

they go badly wrong and black can easily lose a gammon. White’s four-point board should set alarm bells ringing Simply best 11/5*/4 Black remains with excellent outfield coverage even if white enters.

Page 55: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Slot or Coverage?

The lower the point the less likely (or necessary) the slot.

Check for other significant factors Where is the cube?

Page 56: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

The Right Conditions?

Correct Play: 21/19, 3/2

Page 57: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

These are the ideal conditions for slotting a lower point: White has only a two-point board White has an exposed blot in his home board Black will need his 3-pt to win the game Black can’t win with the cube so needs to play aggressively

All the criteria point towards the slot being correct The 2 can be played 14/12 or 21/19 as the two plays are equal

Page 58: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

And finally ……….

Correct Play: 9/6

Page 59: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

Commentary

The most famous slotting question in World Championship history. Should Joe Dwek (black) have slotted with this 21 against Lee Genud? Yes he should by playing 9/6. He doesn’t have a direct cover but the two blots on the 14- and 15pts

give him the equivalent of a direct cover and he must have the 6-pt to win the game.

Genud fanned and then Dwek slotted next turn but Genud entered with 65 hitting two blots and won easily from there.

Remember – two indirect cover numbers are often approximately equal to one direct cover number

Page 60: To Slot or Not to Slot? Chris Bray chris.bray@btconnect.com.

The Play’s the Thing …….