Wednesday, June 15, 2022

Monkeying With ShashChess

     About four years ago I did a post where I looked at, among other things, the SashChess engine, but wasn't too impressed by it. However, a few days ago while looking at the CCRL 40/15 complete rating list SashChess was prominent. 
     On the complete list the top rated engine is Stockfish 15 at 3541. ShashChess 21.1 (a derivative of Stockfish) is rated at 3535 and against Stockfish it has scored +1 -1 =30. The engine seemed to be worth a closer look.
     ShashChess tries to implement the theory of Alexander Shashin as he explains in his book, published in 2013, Best Play: A New Method for Discovering the Strongest Move. I have not read the book, but supposedly he breaks down the position into some kind of mathematical formula that evaluates material, mobility, safety and space. This should lead to finding the proper plan. 
     The concept of space, time and force is not new. Znosoko-Borovsky's 1955 book, The Middle Game in Chess, focused on those elements as did Larry Evans' hack job, New Ideas In Chess, also published in the 1950s. 
     Then there was Horowitz' Point Count Chess in which he listed positional factors that were worth points and anti-positional factors that were negative points. After all the adding and subtracting was done you knew who was better, but not how to utilize your advantage. The whole idea seems similar to counting cards in Blackjack...something that's probably beyond the capability of most of us. 
     The thing is, one can have an advantage in all three elements (space, time and force) and still have an inferior, or even losing, game due to some tactical anomaly. Purdy pointed that out in his writings a long time go. 
     There is a good discussion on the pros and cons of Shashin's method on the book's review on Amazon which you can read HERE. I will leave it to the reader to form an opinion on the practicality of this concept. 
     One reviewer of ShashChess stated that it draws with Stockfish in head to head engine matches, but significantly outperforms Stockfish in puzzle solving and mate-finding. Further, the reviewer stated that Shashchess' developers (ICCF IM Andrea Manzo is the owner and main developer) created it for correspondence chess and he attested that "it is an interesting and powerful analysis tool." 
     The home page for ShashChess gives some helpful information when analyzing with an engine. First, use all the cores. Unless you have a dedicated computer that's not realistic because if you're like me, while the engine is analyzing you'll want to be doing other things on the laptop. I usually use two of the four cores. 
     Regarding MultiPV, i.e. the number of alternate lines of analysis to display, you should specify only one to get the best line. Specifying more lines slows down the search. 
     I thought about trying ShashChess out in correspondence play on Lechenicher SchachServer where engine use is allowed, but decided against it. Why? As I posted back in 2015, on my laptop engines don't come up with the same moves as the same engines do on dedicated computers. That means I have about as good a chance competing at the highest levels on places like ICCF and Lechenicher SchachServer as I do playing over the board against Carlsen and others of that ilk. 
     Unlike in the pre-engine days when we used post cards and the only "help" was Modern Chess Openings, unless you just want to dabble in correspondence chess or don't care about results (highly unlikely) or ratings (also highly unlikely), then correspondence chess is not for you. That's why I suggested the creation of new correspondence chess classes: Beginning Dabbler, Intermediate Dabbler and Serious Dabbler. 
     Way above us Dabblers are the titled correspondence players...those guys with a couple of thousand dollars to spend on hardware/software and a LOT of patience. 
     The SashChess Homepage alo describes an interesting engine option called GoldDigger. I am not sure about other programs, but with Fritz you can turn this option on as follows: 
 
1) Select Load Engine 
2) Highlight the SashChess engine 
3) Click on Advanced 
4) Click on Engine Parameters 
5) Select GoldDigger 
 

     If GoldDigger is activated, the engine favors depth over the pruning of various selectivity techniques. In this way, it can uncover normally hidden possibilities. In this mode, it solves many more hard positions, although it loses slightly in absolute game strength. 
     You will also notice the names of Tal, Capablanca and Petrosian. Depending on the engine's evaluation it has algorithims based on the style of play of those greats as well as "mixed" ones. 
     The engine plays differently based on the evaluation of the position it is analyzing. That is, it classifies the position with "personalities." Petrosian for negative scores (defensive positions), Capablanca for balanced scores, and Tal for positive scores (attacking positions). Apparently by checking one of the boxes the engine will play with that players style only. 
     All in all, SashChess sounds like an interesting engine to monkey around with. Download HERE

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