Return to the Engine Room

Sherwood, Russell  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.

Updated Wednesday, July 8, 2020 by Russell Sherwood

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