Russell Sherwood

Return to the Engine Room

Russell Sherwood  Wednesday, July 8, 2020

It's been sometime since I was last in the Engine room and quite a bit has happened in the world of Chess Engine development in that time!

ASMfish is no more. This port of Stockfish into Assembler had proven very popular with enthusiasts due to its additional speed boost but it is now so far behind Stockfish in terms of development that any speed advantage pales into insignificance compared with the deficits in search and evaluation.

It appeared CFish had gone the same way but in recent weeks an effort has been made to bring the code up to date. CFish offers some speed benefits, so this is worth watching to see if the efforts are successful.

Houdini has had no new releases in several years but in recent months, what is allegedly the source code has appeared in public forums. Whilst the veracity of this is not of interest, it would be surprising to see an updated version of this engine appear in some form.

In terms of other engines outside of the main players the main newcomer has been Ethereal. Whilst not quite at the same level as the top engines it does have an interesting playing style.

Neural net development has continued to advance           

Significant work has been undertaken to make LC0 far easier to install and many specialised nets have been developed, Elo improvement has slowed, and development of Stockfish has been spurred on to compete with LC0.  A neural net is an essential part of an aspiring CC players arsenal, but it is now much easier to achieve for two reasons:

Fat Fritz has been updated and runs well on CPU based hardware (as opposed to LC0 which really requires a high-quality graphics card). Fat Fritz is based on a different network development method but does add to players options.

Stockfish development has thrown up two fascinating projects. Stockfish NNEU is a method to create a neural net which operates with Stockfish. It is early days yet, but early testing shows performance approaching Stockfish itself. In my own research it does show some interesting moves and runs much faster than a LC0 network but as I said early days!  The other project is Stockfish WDL, which is an attempt to generate a Win-Draw-Loss score for Stockfish. This is in exceedingly early days now but does appear to show some promise.

With the release of Fritz 17, we saw the appearance of the Fritz 17 engine (which I believe many users think is Fat Fritz!). Whilst a pleasing upgrade from Fritz 16 (which was simply Rybka modernised) this engine is a long way of the pace in CC terms and should not be utilised as a main engine

Honey is a specialised development of Stockfish which adds several features especially useful for CC players, for example Defensive mode and Deep Profound Analysis. Each release does provide several versions which include the best tweaks of several other engines. Personally, a favourite!

Eman is something of a controversial engine, for non-chess reasons I will not go into and ridiculously hard to get hold of but does provide interesting features including an ability to sniff out interesting moves. Well worth the effort to get hold of!

Bluefish is something of a marmite engine. Its “Bluefish” mode is somewhat misleading as it is simple reports the depth and node count incorrectly. It does, however, tend to utilise a narrower search giving a greater depth. Dependent on position this can either be a game winner or a game loser. Worth a look but personally I would never use it as a main engine

ShashChess has just updated as is an interesting engine, with former CC World Champions and Grandmasters involved in its development. It has three different modes, which either the engine self-selects, or the user can select, which approach the position differently. Well worth a look.

Raubfisch has been around for a long time and includes a lot of CC specific features, including ICCF Mode. Worth close examination.

Komodo has two modes – traditional and Monte Carlo. Both have a following with CC. If you want to use a Monte Carlo engine with a CPU then you probably need to use Komodo. Do not be fooled into thinking Stockfish is far superior simply based on ratings. Komodo plays a much more solid game and tends to be popular with those who prefer solid positions. It of course one of the few commercial engines in this review.

Rating Differences

Russell Sherwood  Tuesday, June 16, 2020

In the postbag (well the electronic one anyway!) I have been asked several questions about the ICCF rating system.  One wide misunderstanding  is about rating points being gained or lost playing against lower rated opposition. 

Looking into it two factors have the most underlying effect on the result – your k value and the difference in rating.

The k value is defined as part of the rating equation:

 

I put a K calculator into the spreadsheet to make life easier, but we can see from the above the k value gets smaller as your rating and number of games completed increase.

From looking at the formula we can see that the k value starts out around 25 and then trends down to around 10 for the majority of players – or 20 if your rating is below 2000. Where do you find your k value – either on the spreadsheet or in your rating forecast on ICCF.com

Once we know this we can determine that the number of rating points lost or gained in a game is calculated from your actual score in the game – your expect score multiplied by your k value.

Your actual score can only take one of three values 0,0.5 or 1. 

Your expected score comes from the difference between you and your opponents rating, by the formula:

Hmmmm…..

In practice this means

Rating difference

Diff%
2552%
5054%
10059%
15063%
20067%
25071%
30075%

 

By a very long and painful journey we come to a number of generalizations, which have been the questions I have been asked:

  1. You have to be rated more than 100 elo more than your opponent to lose more than 1 point from a draw (for most people with a K factor around the 10 mark)
  2. In a two game match (Friendlies in particular), this drops to 50 elo for a “double draw” costing more than 1  point
  3. If the difference in elo is less than 300, than 1.5/2 will be a net rating gain for the higher rated player 
  4. Once the gap is more than 300 elo then 2/2 is required to not lose rating points.

 

Download

Rating system

Neural Nets on the cheap

Russell Sherwood  Tuesday, June 9, 2020

As I finalize an article on setting up Neural Net based engines, it is worth sharing that you do not need to upgrade to an expensive new machine or graphics card to make use of neutral nets.

http://www.ezchess.org/

It is possible to put together a stand-alone unit for a little for a fraction of the cost of a high end PC.  The unit is not super-powered but will out perform most CPU powered versions.  If you are interested in this approach, get in touch 

 

 Thanks to SIM John Claridge for the tip on this!

 

p.s. An even cheaper alternative is https://leelanalysis.com/  which is currently free but in Beta Stage

NN

Counties and Districts Update

Russell Sherwood  Tuesday, June 9, 2020

The 2019-2020 C&D CCC is moving towards an interesting finish, with 20 games remaining on the top tier

https://www.iccf.com/event?id=83944

Hertfordshire top the table, having completed their games but with expected results Essex A look to be heading towards the title chased home by West Wales and Lancashire. The shock of the event is that former powerhouse Yorkshire look to be have been sucked into the relegation battle.

Probably the most interesting game of the event is https://www.iccf.com/game?id=1143988

 

https://www.iccf.com/event?id=83949  

In the 2nd Tier West Wales B look set for promotion 

Euro Team Cup Update

Russell Sherwood  Sunday, June 7, 2020

Following a number of new results our position continues to strengthen in this event.

Currently, we stand at 16-11, with 13 games still in play - so we only need to score 4.5 from 13 to advance, which is looking more than likely

Congratulations to Tony Balshaw, Paul Keevil, Phil Morgan, Fred Clough and Sean Denton in securing wins!

In the other fixtures.

Team AA ScoreB ScoreTeam BRemaing GamesLikely to Advance
Gemany136Noway21Gemany
Gemany1210Slovenia18
Slovenia18.58.5Noway13
 
Italy17.515.5Ukraine7Italy
Netherlands15.513.5Romania11To close to call
Russia1716France7Russia
Spain12.511.5Poland16Spain
Sweden1116Wales13Wales
Euro Team Cup

Interesting Annotated Games

Russell Sherwood  Friday, June 5, 2020

Tim Spanton publishes some interesting annotated games from the BWSTT on his blog

https://beauchess.blogspot.com/2020/06/more-lockdown-chess.html

6BWSTT

Welsh Provisional 2020/3 Rating List

Russell Sherwood  Monday, June 1, 2020

   2020/2ForecastRating Change
ICCF IDTitleNameGamesRatingRank+/-RankRating 
451416IMJohansson, Thomas262578   25780
810209SIMYeo, Gareth3212476101248711
210855IMBalshaw, Anthony525246220224675
810160SIMClaridge, John B.322244530324450
211672IMLockwood, Austin256240140424076
810183IMJones, Ian36423935052392-1
810161CCMSherwood, Russell9902357716238326
810243CCMEvans, Craig18823836-172373-10
810182CCMDean, Philip100234991823556
810212CCMSherwood, Alexander52923568-192351-5
810174CCMBishop, William103232514410234924
810202LGMSherwood, Helen902233013211234818
810208CCMDavies, Adam114233711-11223458
810179 Varley, Peter25233512-11323350
810139CCMAdams, Mark215234210-4142324-18
810163CCMKeevil, Paul17723231511423241
810233CCEScott, Paul34723011601623021
810137 Thornton, John D.2522931701722930
810175 Williams, John L.4422811801822810
810057CCMSinnett, Glyn20622791901922790
810211CCECannon, Dale8822742002022740
810221CCEGibbons, Andrew7422602102122600
810278 Jones, Rhys162149319222258109
810180 Nettles, Paul Eric68224622-12322460
810184 Yüce, Aytaç118223823-12422435
810259CCEDenton, Sean110220728325223023
212222 Morgan, David Philip18222225-12622242
810152 Clough, Fred181221326-12722218
210426 Fordham-Hall, Christopher M.248221326-22822130
810075 Wakeham, Marc R.651223724-5292205-32
810247 Hatchett, Paul6021843003021840
810222 Smith, Andrew173218529-2312173-12
810195 Bevan, Peter M.1272143320322130-13
212420 Thomas, Michael D.132100330332096-4
810061 Griffiths, Martyn J.11220853403420850
212422 Davies, John1220743503520839
810156 Ricketts, Martin88203037136206030
810165 Bailey, Stephen246200438137205046
219118 Robertshaw, Andrew M.239203636-23820360
810248 Hurn, Robert53197441239202450
810256 Jones, Phillip76200339-14020030
810272 Flew, Nick30197441041200026
810189 Alex Bullen29193944242196930
810197 Thomas, Vaughan61191545243194732
810268 McCarthy, Maurice46194043-14419400
810276 Coles, Jon39198340-5451933-50
810204 den Drijver, Danny3519024604619020
810255 Morgans, Justin741893470471880-13
810216 Collins, Eleanor2618744804818740
810133 May, Adam J.5618004904918000
810187 Wilson, Mark3817975005017970
810240 Jones, Dewi1217705105117700
211773 Clark, Richard I.39317705105117700
810237 Rizvi, Nasir2617405305317400
810128 Evans, David R.14167759554171841
810167 McFadden, Wayne4078235517051705
810219 Denham, Colin144170454-25617040
212421 Robinson, Nicola24170454-25617040
810218 Beck, Anthony16169856-25816980
810205 Meara, Paul34169158-15916910
810220 Davies, Jonathan32169856-4601678-20
810251 Soar, Timothy44167660-16116760
810213 Griffiths, Hywel D. R.12167561-16216750
810162 Roberts, David150165362-16316530
810192 Baron, Margaret241162463-1641610-14
810235 Ford, Stephen28158464-16515840
810241 Sipho, Donovan1215706606615700
810257 Burrows, David72158265-2671553-29
810253 Bray, Peter74151469168154127
810198 Thomas, Dennis29152867-2691511-17
810102 Guy, David T.311152168-2701493-28
810181 Hallwood, Reg24148370-17114830
810199 Dahlgren, Paul P.44145671-172147317
810177 Wilding, Arthur83144072-1731425-15
810217 Richards, Michael236133473-17413340
810249 Szakmány, Bence1213077507513070
810254 Jones, Steve74132174-2761299-22
211735 Merrifield, Peter12125876-17712580
810176 Chugg, Malcolm132124577-1781228-17
810293 Jones, Gareth0078-17900
810279 Powell, Andrew0078-17900
810287 Parsons, David0078-17900
810286 Robinson, Josh0078-17900
810294 Walters, Martin0078-17900
810281 Williams, Duncan0078-17900
212907 Dunning, Stephen0078-17900
Rating List

AB & NN - a perfect match?

Russell Sherwood  Wednesday, May 6, 2020

I’ve been working on a number of articles/books/ideas of late. 

One which is close to fruition is guide to engine analysis, which will be published in written and video format for premium members. Any member wishing to get involved for the proofreading of this, please get in touch.

One question I repeatedly get asked is about the difference between the two engines types and their suitability for positions.

As a way of introduction, when we are selecting a move we are broadly examining three characteristics: Tactical, Positional and Strategic.

Tactical:  referring to a sequence of moves that limits the opponent's options and may result in tangible gain

Positional: referring to a sequence of moves, where the structure of the position is examined and improved (e.g. pawn structure and control of open files)

Strategic: referring to the development of a plan, which goes beyond individual moves or sequence of moves.

There is no absolute difference between the characteristics, they should be considered a continuum. In addition, finding a definitive definition is somewhat difficult!

If we attempt to overlay the main engines around at the moment, we find that most of the main Alpha-Beta engines (of which Stockfish is paramount) are excellent in the Tactical sense, weak1 in the positional sense and generally poor in the Strategic sense1

In addition, it is noticeable that some seemingly positional moves are the result of a deep tactical based search!

Many SF clones tend to be slightly stronger in the positional sense, although often as the expense of some tactical benefits.

Komodo (in AB mode) tends to be slightly stronger positionally and slightly weaker tactically and , on occasion , give the impression of playing strategic moves (in the same way that an exhaustive tactical search throws up positional moves, a deeper search with Komodo can throw up moves that appear strategic in nature)

LC0 tends to play good positional moves and many that are almost strategic nature, although much depends on the network in use and the training regime used (which is another article). It is slightly weaker in terms of tactical play (on typical home hardware) Komodo MCTS shows many of LC0’s characteristics but as its evaluation is still “human”, not quite as well.

An aspiring CC player can utilise this to their advantage. Having recently upgraded to fairly high-end hardware I have been observing SF and Neutral Net engines working in tandem. I have tended to observe (assuming I put 3 MPV on the AB engine) four situations:

  1. Both Engines choose the same moves (although not necessarily the same lines)
  2. The AB Engine (Stockfish) finds a good (tactical) move very quickly and the NN engine significantly longer (typically the move starts towards the bottom of the evaluation and slowly improves its evaluation)
  3. The NN finds a good move , which SF either (a) tends to find after only a very deep search or only after it is “shown” the line.
  4. Both suggest a very different set of moves.

 

If we examine these situations, A happens about 75% of the time, B and C about 10% each and D around 5%. Utilising B and C and checking between the two engines can generate a number of winning “moves”.  D is perhaps the most interesting as this is the area where strategic planning comes into play and is the margin that the highest rated players reside in!

(Note the practical application of this will be covered in the Engine Analysis guide mentioned earlier.

What type of positions do these four scenarios tend to crop up in? We will cover that next time!

 

(1)It is worth noting that “weak” in this sense tends to be mean about 2400 elo!

AnalysisEngines

A Williams Dragon

Russell Sherwood  Friday, April 24, 2020

Aa annotated game (Paul Scott) from the Evans Tournament. 

 

Woah, we're half way there (almost!)

Russell Sherwood  Wednesday, April 22, 2020

The Latest forecast is Wales 23- Sweden 17 in the Euro Team Cup!  A victory here should lead to a juicy tie with one of the highest rated federations!

 

(The photo - I did have hair like that in the 80's - a joke you will only get if you are in the know!)

EuroTeamCupWales-Sweden
Welsh Correspondence Chess FederationBritish Correspondence Chess AssociationSchemingMind Internet Correspondence Chess ClubSocial Correspondence Chess AssociationNational Correspondence Chess ClubWelsh Chess UnionInternational Correspondence Chess Association