Benjamin

version 2.0


Tactical Analysis Engine

Benjamain 2.0 goes one step further than the first version, the focus of version 1.0 (see below) was on playing style, version 2.0 is meant as an analysis tool to quickly find tactical shots. We ran a tactical suite of 100 positions (mainly positions from the excellent CSS-WM test) in the style of the Speedy Rating List and the results are stunning.

Benjamin 2.0 is pre-installed in the Arena interface ready to use, double click on Arena.exe (tactics.epd is automatically loaded), press Analyze and watch the diiferences between the standard ProDeo 2.2 and Benjamin 2.0, see screenshot.

Credits

ARENA is copyrighted © by Martin Blume and its

distribution is limited to the ARENA website only.

Benjamin 2.0

10.5 Mb

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The Gambit version of ProDeo

This year (2020) it's 40 years ago I started chess programming, from REBEL 1.0 -> REBEL 12 and after my retirement from the competition (2003) the free versions ProDeo 1.0 -> ProDeo 2.9, the 2.2 version (2016) being the last serious engine update whereafter development stopped.

 

Inspiration returned, an afterthought version after all, Benjamin (the last-born of Jacob's 12 sons) is the Gambit version of ProDeo hardly without loss of strength. Living in the age of the almighty Stockfish, Leela (and friends) improving playing style is a nice new challenge. Examples of Benjamin, first some cherry picked positions Benjamin is superior to the new Stockfish 11.

1.. Nb4

Benjamin      0:03

ProDeo 2.2    0:25

Stockfish 11   1:43

1. Nxb5

Benjamin      0:10

ProDeo 2.2    0:22

Stockfish 11   8:11

1. e6

Benjamin      0:00

ProDeo 2.2    0:00

Stockfish 11   0:13

1. g4!

Benjamin      0:02

ProDeo 2.2    0:08

Stockfish 11   0:03

1. Rf6!

Benjamin      0:12

ProDeo 2.2   not after 10:00

Stockfish 11   1:04

Mate in 30

Benjamin      0:00

ProDeo 2.2    0:00

Stockfish 11 not after 10:00

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Benjamin vs ProDeo 2.2

only 3, there are

too many

1. Bb6

Benjamin      0:00

ProDeo 2.2   0:07

1. Bxe4

Benjamin      0:03

ProDeo 2.2   0:30

1. Rxc6

Benjamin      0:01

ProDeo 2.2   1:51


Used EPD's

r5k1/2p1b1p1/6bp/p4P2/q3pP2/2PnB2P/PP1N4/KR3Q1R b - - 0 0 bm Nb4;
r1bk3r/1pp2pp1/p2p1n1p/5q2/8/4BN2/PPPQ1PPP/3RR1K1 w - - 0 0 bm Bb6;
r1bqkb1r/4pppp/p1p5/2ppP3/8/2P2N2/PPP2PPP/R1BQR1K1 w kq - 0 0 bm e6;
r3qrk1/4bppp/4p3/p2pP2Q/1p1B4/1PpPP3/P1P2RPP/5RK1 w - - 0 0 bm Rf6;
r3k2r/4b2p/p1n3pN/1p1q1p2/5B2/3p1P2/PP4PP/2RQR2K w kq - 0 0 bm Rxc6;
r1bk1n1r/pp1n1q1p/2p2p1R/3p4/3PpN2/2NB2Q1/PPP2PP1/2K1R3 w - - 0 0 bm Bxe4;
7r/1k2P2P/4p3/1pp5/8/2pp4/1n3PP1/R4K1R w - - 0 0 bm g4;
8/4kpbn/p1p3p1/Pp2p2p/1P2Pn2/N1P1BP2/5P1P/5BK1 w - - 0 0 bm Nxb5;
5n2/B3K3/2p2Np1/4k3/7P/3bN1P1/2Prn1P1/1q6 w - - 0 0 bm Neg4+; id M30;

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The Gambit algorithm


The Gambit algorithm is controlled by a parameter in the benjamin.eng script file in the personal folder.


[Gambit = 120]


The paramter is extremely sensitive to changes, the default setting is 120, increasing or decreasing it with a value of 10 may already have big consequences to its playing style. For instance, a value of 25 will change Benjamin into a boring and weaker engine, a value of 200 may cause Benjamin to play unsound moves (c.q. sacrifices).


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Strength comparison

Benjamin vs ProDeo 2.2


Regarding strength, based on playing 5000 bullet self-play games we get:

Gambit value

ProDeo 2.2

120

-28 elo

110

-15 elo

100

-8 elo

95

-3 elo

90

+3

85

0

80

+3

Not happy?


Use the ProDeo.eng, it will exclude the Gambit algorithm, the engine will play as you are used from ProDeo with an extimated elo gain of 10-15.


All testing is based on bullet testing, what that means on longer time controls is unclear.


Enjoy. 

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Download and installation

Unzip the archive somewhere on your hard drive.


Benjamin 1.0 (Winboard and UCI compatible) which you can run in multiple Interrfaces, among them the freeware Arena.


To run Benjamin you will need to announce the engine first.


  • Under Chessbase this means: Engine -> New UCI engine -> Browse -> RebelUCI.exe


  • Under ARENA do: Engines -> New Engine -> UCI -> RebelUCI.exe


  • Under ChessPartner do: Extra -> Engine Import Wizard -> Winboard -> Install -> Benjamain.exe



Benjamin 1.0

Approx 4 Mb