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To Slot or Not to Slot?

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. Contents. General Principles The Opening The Middle Game The End Game. General Principles.

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To Slot or Not to Slot?

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

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

  3. Contents • General Principles • The Opening • The Middle Game • The End Game

  4. General Principles

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. The Opening

  10. The Opening Roll – Black to Play 21, 41 or 51 Correct Play: Your choice!

  11. 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.

  12. The First Response Correct Play: 13/9, 6/5

  13. 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.

  14. And slightly later ….. Correct Play: bar/21, 6/5

  15. 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.

  16. 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

  17. The Middle Game

  18. Back in the 1970’s Correct Play: 24/21, 24/23

  19. 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.

  20. Back in the 1970’s (2) Correct Play: 8/2*/1

  21. 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

  22. 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?

  23. Simple Start – Slot, Split or Smooth? Correct Play: 6/5

  24. 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

  25. Basic Question – Split or Slot? Correct Play: 13/8, 6/5

  26. 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.

  27. Is now the time? Correct Play: 8/2, 8/7

  28. 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!

  29. … or now? Correct Play: 13/7, 13/8

  30. 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

  31. Slightly more difficult Correct Play: 15/11, 6/5

  32. 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

  33. … and more difficult again Correct Play: 13/9, 24/23

  34. 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

  35. And really difficult! Correct Play: 23/18, 15/14!!

  36. 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

  37. Piano or Forte? Correct Play: 14/5

  38. 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.

  39. Piano or Forte (2)? Correct Play: 21/16, 11/10 or 21/15

  40. 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.

  41. Pick and Pass or Not? Correct Play: 5/3*/2

  42. 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

  43. Desperation Stakes? Correct Play: 8/4, 24/23

  44. 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!

  45. The End Game

  46. 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)

  47. Open 6-pt Correct Play: 14/6

  48. 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.

  49. Open 5-pt Correct Play: 20/14, 13/11

  50. 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

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