Backgammon Problems by Mike Corbett
a review by Ray Kershaw

 


These days an enormous amount of quality backgammon analysis is available for free or for a very modest subscription on the internet.  My favourite sites are GammonU with Kit Woolsey’s commentary on the matches which he has been playing for many years against his readers;  Stick Rice’s bgonline with its lively discussion board;  and Gammon Village with well researched articles by top players including Steve Sax, the late Walter Trice and Douglas Zare.

This raises the question whether it is still worth buying backgammon books, given that with small circulations they are quite expensive.

My answer is a definite yes when the book has value not just for a first read but also as a reference work for the future.  This requires the author to put in a lot of hard work both to assemble his material and equally important to present it in a clearly written, well ordered manner without spelling, factual and grammatical errors.  (I say “his” because I am not aware of any recent backgammon book by a female.)

Recent books which pass this test include Modern Backgammon by Bill Robertie, Backgammon Boot Camp by Walter Trice, Backgammon Praxis by Marty Storer, Backgammon Openings by Nack Ballard and Paul Weaver, and What Colour is the Wind ? and Second Wind by Chris Bray.

Mike Corbett’s Backgammon Problems costs over £30 from Chris Ternel’s Backgammon Shop.  It is poor value for money which would be much better spent on any of the above books.

Backgammon Problems is a collection of articles originally produced “to amuse the readers of a quarterly magazine”.  The principal theme is the identification of positions where the Snowie evaluation of the best play is contradicted by the Snowie rollout.  Corbett also indicates where he thinks that even the rollout is not to be trusted because of systematic misplay by Snowie of the position.

This is an important topic.  Rollouts take time and the Snowie user needs to know when it is worthwhile to query a Snowie evaluation.  Corbett can be commended for making some progress but sadly the book is woefully short of what would be acceptable as a useful scholarly treatise.  Here are some of the reasons:

·         The book has 205 pages which you might think respectable in terms of quantity.   But an astonishing 23 pages are blank.  And the non-blank pages are in an unusually large font.

·         Corbett admits to a “somewhat liberal interpretation of the English language”.  I would guess that Corbett has little experience of writing.  Apart from typographical, spelling and punctuation errors, he writes sentences like this which you have to read twice:  “Critical mass is a threshold through which no structure may pass unchanged, and while White’s position appears stable, it is bound inexorably for structural reshuffling.”  There is a generous spattering of pseudo-legal terms like herein, therein and wherein.  (Compare the simple, lucid prose of Robertie, Ballard and Weaver, and Jeremy Bagai.)  And Corbett frequently writes sentences which are split by almost a page of diagrams and Snowie output.

·         The presentation of the rollout results is sloppy.:

o        Settings:  number of games;  played (for example) 3-ply (precise), cube 3-ply;  settlement (for example) at 0.550 at 4pts; seed 1 without race database (for example).  Sometimes Corbett gives all these settings, sometimes just some of them and sometimes none at all.  The absence of a full specification of all the settings makes it impossible for anyone to replicate Corbett’s output.  (Indeed, Corbett does not even say which version(s) of Snowie he has used.)

o        95% confidence interval:  Again sometimes he gives this and sometimes he does not.  He does not seem to have actually used the confidence intervals to establish whether a rollout has yielded a statistically significant difference between two plays.  It seems clear to me that there is often no such significant difference.

When and why a Snowie rollout contradicts its evaluation is an admittedly very difficult topic, presumably being addressed by current bot developers.  Corbett has identified a few biases in Snowie’s  evaluations and his findings may be of interest to enthusiastic students of backgammon bots.  But the general student of backgammon is advised to buy the other books cited above before spending £30 on Backgammon Problems.

I like to encourage backgammon scholarship and I take no pleasure in discouraging buyers of this book.  But a review should be honest.   Flattering reviews elsewhere by distinguished players are unfortunate.
 


Many thanx to Ray Kershaw for this review - published 2nd October 2009


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