I have released version 2 of my chess engine. I’ve rewritten the engine from scratch in a more procedural style code- as opposed to the sub-optimal (for chess engines at least) object-oriented style I used in MadChess 1.x.
The engine is about 115 – 160 Elo stronger than its predecessor, depending on time control. I estimate it is about 2350 Elo.
Source code and EXEs available on the Downloads page.
I have added parameters to limit the playing strength of MadChess 2.0 Beta.
The simplest way to limit the playing strength of MadChess 2.0 Beta is to set the LimitStrength and Elo parameters. The engine will automatically configure material scores and positional knowledge.
In addition, the engine will configure search speed (Nodes Per Second), move error, blunder error, and blunder percent based on the Elo value.
MadChess 1.4 participated in Graham Banks’ 54th amateur tournament in division 6.
1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6
1 PikoSzachy Extreme ** 00 11 ½½ 1½ 11 11 10 11 01 11 ½1 01 11 1½ ½1 22.0/30
2 Lozza 1.15 64-bit 11 ** 01 01 ½½ ½½ 11 ½1 ½½ ½1 ½1 1½ 10 1½ ½1 ½1 20.5/30
3 Tigran 2.4n 64-bit 00 10 ** 00 10 1½ ½1 11 11 1½ 1½ ½½ 11 1½ 11 1½ 20.0/30
4 Jazz 840 64-bit ½½ 10 11 ** 01 ½½ 00 1½ 11 1½ 0½ ½1 11 10 01 10 18.0/30 267.50
5 Gibbon 2.69a 64-bit 0½ ½½ 01 10 ** ½½ ½1 10 10 1½ ½½ 11 10 1½ 11 10 18.0/30 254.50
6 MadChess 1.4 64-bit 00 ½½ 0½ ½½ ½½ ** 0½ 0½ ½1 1½ ½0 01 ½1 01 11 ½1 15.0/30 207.75
7 Schooner 1.4.1 64-bit 00 00 ½0 11 ½0 1½ ** ½1 ½0 11 10 10 ½0 1½ ½½ ½1 15.0/30 207.00
8 FireFly 2.7.0 64-bit 01 ½0 00 0½ 01 1½ ½0 ** 00 ½1 ½½ 11 11 ½1 ½0 ½1 15.0/30 205.50
9 Waxman 2014 00 ½½ 00 00 01 ½0 ½1 11 ** ½0 01 1½ 11 01 ½1 1½ 15.0/30 201.00
10 CyberPagno 2.2 64-bit 10 ½0 0½ 0½ 0½ 0½ 00 ½0 ½1 ** 1½ 1½ 10 ½1 ½½ 1½ 13.5/30
11 Exacto 0.e 64-bit 00 ½0 0½ 1½ ½½ ½1 01 ½½ 10 0½ ** 0½ 00 01 ½½ 1½ 12.5/30
12 ChessKiss 1.7c 64-bit ½0 0½ ½½ ½0 00 10 01 00 0½ 0½ 1½ ** 10 00 11 11 12.0/30
13 Protej 0.5.8c 10 01 00 00 01 ½0 ½1 00 00 01 11 01 ** 10 00 ½1 11.5/30 166.00
14 Orion 0.2 00 0½ 0½ 01 0½ 10 0½ ½0 10 ½0 10 11 01 ** ½0 ½½ 11.5/30 161.75
15 Nemeton 1.2 0½ ½0 00 10 00 00 ½½ ½1 ½0 ½½ ½½ 00 11 ½1 ** 10 11.5/30 159.50
16 Absolute Zero 2.4.0.0 64-bit ½0 ½0 0½ 01 01 ½0 ½0 ½0 0½ 0½ 0½ 00 ½0 ½½ 01 ** 9.0/30
I added rook and queen on 7th rank evaluation to MadChess 2.0 Beta. The code awards a bonus for a rook or queen on the 7th rank if the enemy king is on the 8th rank (its 1st rank).
Also, I removed late move pruning. (When I implemented late move pruning in build 44 it added 39 Elo to the playing strength of MadChess 2.0 Beta.) I replaced it with more aggressive null and late move reductions, and more aggressive futility pruning, but found it decreased the playing strength. Next, I restored late move pruning and left in the aggressive reductions. I found the strength increased, but not quite back to where it had been. I discovered a non-linear relationship between these search techniques. The combined strength of null move reductions, LMR, LMP, and futility pruning is not additive. I experimented with various parameter configurations before deciding to abandon LMP. It took 300 hours of testing to confirm the revised search was equivalently strong to the search with LMP.
This added 20 Elo to the playing strength of MadChess 2.0 Beta.
MadChess 2.0 2306.9 : 1600 (+835,=299,-466), 61.5 % vs. : games ( +, =, -), (%) : Diff, SD, CFS (%) Glass 1.6 : 100 ( 22, 24, 54), 34.0 : -140.1, 15.0, 0.0 RomiChess P3L : 100 ( 20, 20, 60), 30.0 : -133.7, 16.2, 0.0 OliThink 5.3.2 : 100 ( 23, 20, 57), 33.0 : -109.7, 15.5, 0.0 Myrddin 0.87 : 100 ( 31, 21, 48), 41.5 : -75.0, 17.3, 0.0 Sungorus 1.4 : 100 ( 49, 15, 36), 56.5 : -3.1, 8.2, 35.2 FireFly v2.6.0 : 100 ( 47, 31, 22), 62.5 : +89.0, 10.0, 100.0 ZCT 0.3.2450 : 100 ( 42, 28, 30), 56.0 : +94.7, 10.8, 100.0 Beowulf 2.4 : 100 ( 59, 19, 22), 68.5 : +97.1, 13.0, 100.0 Jazz v444 : 100 ( 60, 17, 23), 68.5 : +108.9, 10.0, 100.0 Brainless 1.0 : 100 ( 57, 17, 26), 65.5 : +148.2, 17.8, 100.0 Wing 2.0 : 100 ( 61, 20, 19), 71.0 : +177.5, 10.1, 100.0 BikJump v2.01 : 100 ( 61, 22, 17), 72.0 : +198.9, 10.7, 100.0 Matheus-2.3 : 100 ( 66, 19, 15), 75.5 : +220.5, 10.7, 100.0 Monarch 1.7 : 100 ( 72, 12, 16), 78.0 : +245.5, 11.0, 100.0 BigLion 2.23w : 100 ( 82, 7, 11), 85.5 : +277.1, 9.4, 100.0 Sharper 0.17 : 100 ( 83, 7, 10), 86.5 : +289.8, 10.8, 100.0
| Feature | Category | Date | Rev1 | WAC2 | Elo Rating3 | Improvement |
|---|---|---|---|---|---|---|
| Rook And Queen On 7th Rank | Evaluation | 2015 Aug 20 | 123 | 279 | 2307 | +20 |
| Knight Outposts | Evaluation | 2015 May 27 | 83 | 276 | 2287 | +25 |
| Tune Reductions And Pruning | Search | 2015 Apr 26 | 74 | 275 | 2262 | +20 |
| Bishop Pair | Evaluation | 2015 Apr 15 | 69 | 275 | 2242 | +18 |
| Free Passed Pawns | Evaluation | 2015 Mar 10 | 59 | 270 | 2224 | +31 |
| Unstoppable Pawns Draws, Material Trades |
Evaluation | 2015 Jan 31 | 52 | 270 | 2193 | +39 |
| Late Move Pruning | Search | 2015 Jan 10 | 44 | 273 | 2154 | +39 |
| History Heuristic Late Move Reductions |
Search | 2015 Jan 04 | 40 | 275 | 2115 | +50 |
| Killer Moves | Search | 2015 Jan 03 | 38 | 275 | 2065 | +61 |
| Futility Pruning | Search | 2014 Dec 29 | 37 | 256 | 2004 | +54 |
| Null Move Quiescence Recaptures |
Search | 2014 Dec 28 | 34 | 242 | 1950 | +46 |
| King Safety | Evaluation | 2014 Dec 24 | 32 | 225 | 1904 | +27 |
| Piece Mobility | Evaluation | 2014 Dec 16 | 29 | 225 | 1877 | +64 |
| Draw By Repetition Bug | Evaluation | 2014 Dec 10 | 27 | 225 | 1813 | +47 |
| Passed Pawns | Evaluation | 2014 Dec 09 | 26 | 225 | 1766 | +72 |
| Time Management | Search | 2014 Dec 08 | 25 | 231 | 1694 | +24 |
| Delay Move Generation Aspiration Window Bug |
Search | 2014 Dec 02 | 23 | 231 | 1670 | +44 |
| MVV / LVA Move Order Draw By Insufficient Material Move List Overflow Bug |
Search | 2014 Dec 01 | 22 | 235 | 1626 | +30 |
| Tapered Evaluation MG and EG Piece Location |
Evaluation | 2014 Nov 29 | 21 | 234 | 1596 | +107 |
| Alpha / Beta Negamax Aspiration Windows Quiescence, Hash Material, Piece Squares |
Baseline | 2014 Nov 25 | 20 | 236 | 1489 | – |
MadChess 1.4 participated in Graham Banks’ 53rd amateur tournament in division 6.
1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8
1 Donna 2.1 64-bit ** 1½ 1½ 1½ ½½ 01 ½1 ½½ 1½ ½1 11 ½0 11 ½1 11 11 11 11 26.0/34
2 Ares 1.005 64-bit 0½ ** ½½ ½0 1½ ½1 01 1½ 1½ ½½ 11 11 1½ 1½ 11 11 11 11 25.0/34
3 Carballo 1.2 0½ ½½ ** ½½ 01 ½½ ½½ ½½ 1½ ½1 11 ½1 10 01 11 1½ 1½ 11 22.0/34
4 Myrddin 0.87 64-bit 0½ ½1 ½½ ** 1½ ½1 ½1 01 1½ 1½ ½0 ½½ ½½ 01 11 ½0 11 11 21.5/34
5 Tigran 2.4n 64-bit ½½ 0½ 10 0½ ** ½1 1½ 11 ½½ 11 10 10 00 1½ 11 ½1 ½½ ½1 20.5/34
6 Jazz 840 64-bit 10 ½0 ½½ ½0 ½0 ** 11 11 00 ½½ 11 ½1 10 ½1 0½ 01 ½1 10 18.5/34
7 CyberPagno 2.2 64-bit ½0 10 ½½ ½0 0½ 00 ** ½1 10 01 01 ½1 1½ 11 ½0 00 ½1 11 17.0/34 269.25
8 Nemeton 1.2 ½½ 0½ ½½ 10 00 00 ½0 ** 11 00 01 ½½ 1½ 11 1½ ½0 1½ 11 17.0/34 266.25
9 Exacto 0.e 64-bit 0½ 0½ 0½ 0½ ½½ 11 01 00 ** 0½ 01 ½½ 10 0½ 11 01 11 11 17.0/34 263.25
10 FireFly 2.7.0 64-bit ½0 ½½ ½0 0½ 00 ½½ 10 11 1½ ** 0½ 1½ 11 11 ½0 11 00 00 16.5/34
11 Protej 0.5.8c 00 00 00 ½1 01 00 10 10 10 1½ ** ½1 10 01 10 01 ½½ ½1 15.0/34
12 Lozza 1.15 64-bit ½1 00 ½0 ½½ 01 ½0 ½0 ½½ ½½ 0½ ½0 ** 1½ 11 00 11 0½ 0½ 14.5/34 244.00
13 Gibbon 2.69a 64-bit 00 0½ 01 ½½ 11 01 0½ 0½ 01 00 01 0½ ** 00 ½1 10 01 11 14.5/34 235.50
14 MangoPaolaAjedrez 4.1 ½0 0½ 10 10 0½ ½0 00 00 1½ 00 10 00 11 ** 1½ 11 01 ½0 13.5/34 220.00
15 Orion 0.2 00 00 00 00 00 1½ ½1 0½ 00 ½1 01 11 ½0 0½ ** ½1 ½1 ½1 13.5/34 195.50
16 MadChess 1.4 64-bit 00 00 0½ ½1 ½0 10 11 ½1 10 00 10 00 01 00 ½0 ** 10 01 12.5/34
17 PikoSzachy Extreme 00 00 0½ 00 ½½ ½0 ½0 0½ 00 11 ½½ 1½ 10 10 ½0 01 ** 01 12.0/34
18 Absolute Zero 2.4.0.0 64-bit 00 00 00 00 ½0 01 00 00 00 11 ½0 1½ 00 ½1 ½0 10 10 ** 9.5/34
I work as a Software Architect at an insurance company. We're building a modern tech stack in the cloud using C#, Azure, ASP.NET Core, Angular, TypeScript, etc.
I've always been interested in chess (a game of complete information) and poker (a game of incomplete information). This is my attempt to write chess-playing software. I'll get to poker later.
You may be interested to explore my general programming blog, ErikTheCoder.