7thWorldChessSoftwareChampionshipJanKrabbenbos,JaapvandenHerik,GuyHaworthThe7thWorldChessSoftwareChampionshipstartedonJuly1,2017.Sevenprogramsparticipatedinaroundrobintournamentofsevenrounds.ThetournamenttookplaceattheLeidenUniversityandisorganizedbytheICGA,LIACSandLCDS.ThesponsorsareOracle,themunicipalityofLeiden,LeidenUniversity,FacultyofScience,ICGA,iSSC,SurfSaraandDigitalGameTechnology.Itisheldinconjunctionwiththe23ndWorldComputerChessChampionship,20thComputerOlympiadandthe10thComputersandGamesconference.

Round1 Chiron–Komodo½-½ Jonny–TheBaron1-0 Ziggurat–Shredder0-1 ChessEbbiz9-byeWorldComputerSoftwareChampionKomodostartedthetournamentagainstChironwhichisconsideredanoutsider.FromaquietGuiccoPianissimoitwasclearthatwhitetriedtokeepitssmalladvantageaslongaspossible.Komodoshowedtoughcounterplaybutcouldnotturnthetables.ThebalancewasnotdisturbedalthoughKomodoattemptedstrongly.TheaudiencewassurprisedontheresistanceChironoffered.StillChironmanagedtokeepitthiswayandthegameendedinadraw.Jonnyusuallyplayson2400cores.IntheWCSCithastoobeytheplatformruleswhichconstituteplayingwithoneprocessorcontaining4coresandhavingthepossibilitytouse8threads.ThespeedoftheIntelI7processoris3.4GHz.ThishardwarewassufficienttoshowitssuperioritytotheBaron.TheyplayedaKingsIndiangamethatfollowedthebooksupto19.…b6.Atleastthismovewasnotinthebook,butmaybeplayedinotherhumangames.SlowlyJonnysawopportunitiestotakeinitiativesonthekingside.Itsmove30.g4madehisplansclear:openingtheg-fileandpenetratingalongthatlineintotheblackfortress.Itwasalongrunstrategybutitworkedoutwell.TheworsepointfortheBaronwasthatitcouldnotfindaweakspotinwhite’sposition.Finallytheblackpositioncollapsedcompletelyandsoonthereafterthegameswasover.

r1r2nk1/1npb4/1p1p1q1b/3P1p2/1PPNpPPp/4B2P/3QB3/R3RN1Kb-g3030Shredderplayedasemi-SlavagainstZiggurat.Theyfollowedaknownbooklineuptomove17.TheautonomousthinkingprocessthereafterwasinfavourofShredder.SinceZigguratfeltthesameitlookedforunexpectedmovesandlandedatthesameideaasplayedbyJonny.Herethemoveg2-g4hadhowevermoredrawbacks.Blackwasalertandreactedaccordinglywhichimpliedthatwhitewasfacingamultitudeofblackpiecesenteringitsposition.Thedefencewasverydifficultandtheprogressionoftheblackpieceswasunstoppable.Thecomplicationsontheboardwereallinfavourofblackwhoendedthegamewithanicecombination(34.…Bxb4).Soonthereafterwhiteresigned.

5bk1/p1r2p2/1npq2p1/Q3p2p/3rP1P1/PP2NB2/2R2P1P/5RK1b--025Soafteroneroundwehavetwoleaders:1-2Shredder,Jonny(1outof1).

Round2 TheBaron–Ziggurat1-0

Komodo–Jonny½-½ ChessEbbiz9–Chiron0-1 Shredder-byeTheBaronshowedgoodunderstandingoftheSicilianvariationthatoccurredontheboardinitscontestwithZiggurat.Onmove12theylefttheopeningbook.InthenextfivemovesTheBaronmanagedtomanoeuvreitspiecestoexcellentplaces.Fromthatmoveonwardsblackhastosolveoneproblemaftertheother.Mostdangerousfortheblackkingwerethetwobishopsonthediagonalsb3-g8andc3-h8.Althoughblackwasinventiveinfindingmanyescapes,intheenditcouldnotpreventthatthepowersofthebishopswerestrongerthanitsdefense.Whitegainedafullpointbyaniceconcludingcombination.Komodo–Jonnywasameetingbetweenthetwotopprogramsofthismoment.Bothwereeagertowin.Komodo,playingwhite,waseagertousethatinitiativeforanattempttoimprovehisscoreagainstJonny.Sincebothprogramsplayabovehumanworldchampionshiplevelitisdifficulttocriticizethem.Wecanonlyfollowthewisecommentsbytheprogramsthemselvesorbyotherprograms.Therewerechancesforbothsidesanditmustbesaidthattheypostdifficultchallengestoeachother.Oneexamplecanbeseeninthediagrampositionwherewhiteplayed41.Rg3.Hereblackconsideredthreepossiblemoves:41.…R8c4,41.…Rac4andplayedfinally41.…Ra7.Thegameisajoytoreplayandanalyse.Wearesurethatmanyinterestingvariationswillarisefromaccurateanalysis.Howeverforthespectatoritlookedthateverytrialtoobtainadvantagecouldberefutedbyanadequatemovethatshowedalmostthereverse.Bothsidesenjoyedplayingsothegameendedfinallyinatotallydead-endposition.Forsurethehardwareusedatbothsideswasexhausted.

2r2bk1/3N1pp1/3qp2p/1P1p4/r2P1P2/pR5P/P5PK/1R1Q4w--540ThematchChessEbbiz9versusChironbroughtusbacktotheoldtimes.Thensurprisingmoveswerepossiblesinceprogramshadsometimesexcentrique

ideasonthevalueofthepiecesandthequeen.Inthecurrentgamewebelieveamistakedecidedthegame.InaScottishgameapinnedpawnwasstillmoved,sacrificingthequeenandthuslosingthegame.AftertworoundstheleadisbyJonnyandChironwith1.5outof2.

Round3 Jonny–ChessEbbiz91-0 Ziggurat–Komodo0-1 Shredder–TheBaron1-0 Chiron-byeInthethirdroundJonnyestablisheditsleadingpositionbyeasywinagainstChessEbbiz9.Apparentlythelatterprogramhasnotrecoveredfromitsgenerosityingametwoandsacrificedagainapiecewithoutanycompensation.Notsurprisinglythegamewasoverratherfast.AwinforJonny.ThegamebetweenZigguratandKomodostartedwithpromisesbutinthetransitionfromopeningtomidgameZigguratclearlydidnotfollowawellchosenstrategy.Thetacticallineitchoseafter21.…c5didnotbringhimanychanceforanequalgame.Thewhitequeenwaschasedovertheboardanddidfindasafetyplace.Forsecuringitsqueenwhitehadtoacceptabadpositionforitspieces.Thatwasthestartofadeteriorationofitsposition.Blacksoonresigned.Shredder-TheBaronshowedcharacteristicsofagamebetweenanunderdogandandasuperiorprogram.TheunderdogshowstheBlumenfeldgambit.Thestrongerprogramwastrickedintodifficultchoices.However,itfounditswayrathereasilyandavoidedthepitfalswhichweregiventohim.Whitesacrificedtheexchangeforanoverwhelmingpositionandblackhadtoconcedethathisstrategyhadfailed.TherewasnotimeforrepackingandthustheBaronrathersoonthrewthetowelinthering.Afterthreeroundstheleaderis1.Jonny2.5outof3.2-3KomodoandShredder2outof3.

Round4 Komodo–Shredder½-½ ChessEbbiz9–Ziggurat0-1 Chiron–Jonny½-½ TheBaron-byeInthegameKomodo–Shredderthewhiteplayersacrificedapawnforinitiativeagainsttheblackkingandalongthecenterlines.Clearlywhitehadsomepressure,someplayandsomechances.Howeverblackdefendedsecurelyandaccurately.Thebestwhitecouldachieveisregainingitspawn.Thereafterapositionoccurredwithweakspotsatbothsides.Whitetriedtoexploittheblackweakspotbutblackrepliedintherightway.Theideaofexploitingweakspotsledtoarepetitionofmoves.So,drawwasagreed.

TheChessEbbizprogramwasfacingthesamebugasintwoearliergames.Beforethetournamentitpossessedgoodcredentialsandtheauthorthoughtthathehadimproveditsplayingstrengthbysomelastminichanges.Thereverseactionhadtakenplace.Theprogramhadworsenedandthedepreciationfortheownqueenwasleadinginthedecisions.Aclearlossafteracompletelywrongqueencapture.Chironisshowingitscapabilitiesinthistournament.InitsgameagainstJonnyitplayedtheyGuiccoPianissimoopeningwhichcanbetranslatedasquiet,quiet,quiet.Thiswasexactlythecourseofthegame.Pieceswenttosquarestobeexchangedandotherpieceswerecalleduponcentralactionsbutthemaingoalwastheexchangeofthesepieces.Inaveryshortperiodsevenpieceswereexchangedandpawnssufferedfromthesamefaith.Adrawwasinevitable.AfterfourroundsJonnyleadsby3(outof4)followedbyShredder2.5(outof3)andKomodo2.5(outof4).

Round5 Ziggurat–Chiron0-1 Shredder–ChessEbbiz91-0 TheBaron–Komodo0-1 Jonny-byeZigguratandChirontestedatheoreticalvariationwhichwasintheirdatabase.Zigguratfollowedfor15movesitsopeninglibrary.AfterZiggurathatleftthebookChironcontinuedforanothertenmoves.Soonecanarguethatthegamereallystartedonmove26.Thegamecanbecharacterizedaswhiteplayingcarefullyandcautiouswhereasblackplayedactivelyandevenaggressively.Thedifferenceinplayingstyleresultedinaquiteactivepositionfortheblackqueen.After34.…Qc2whitewasindanger.Blackwonapawnandsoonthegame.ThisimpliedthatChironsecuredtheplaceamongthebestfour.ShredderhadawalkoversinceBrunoBrashadbeenunabletorepairtheillnessofhisprogram.Onmove12Shredderthankedforthepieceofferbyblackandsoonwonthegame.TheBaronhadseriouslypreparedforitscontestwithKomodo.TheBenoniDefencewasplayedwithremarkableenergybywhite.Onmove7Komodowasoutofbook.However,itplayedthenewpositionsowellthatTheBaroncouldnottakeadvantageofitspreparations.KomodotrickedTheBaronintoaturmoilofcombinationsthatstartedwith10.…b5and11.Nxb5.Seethediagram.Thebattleofcaptures,threatsandrecapturesfinallyresultedinakindofmaterialbalance.However,thebalanceoftwopiecesagainstrookandpawnturnedouttobeclearlyinfavourofKomodo.AlthoughTheBaronwasalertonmanytricks,itcouldnotpreventthatKomodomadeprogressandfinallytransferredthegameintoawonendgame.

r1bq1rk1/p4pbp/n2p1np1/1ppP4/5B2/1QN1PN2/PP2BPPP/R3K2RwKQ-011Afterfiverounds,itisclearthatthechampionwillcomefromoneofthefollowingfourprograms:1.Shredder3.5(outof4)2.Komodo3.5(outof5)3-4.ChironandJonny3(outof4).

Round6 ChessEbbiz9–TheBaron0-1 Chiron–Shredder0-1 Jonny–Ziggurat1-0 Komodo–byeThegameChessEbbiz9–TheBaronhadanoriginalstart.ThistimeChessEbbiz9seemedtobeabletobuildupanicepositionwithmuchinfluenceinthecenter(seediagram).Howeverblackhadapowerfulreplyatitsdisposalwhichimmediatelyendsthegame.Themove16.…Nd5.After17.exd5follows17.…Bxb4.Therewasnoescape.HenceTheBaronwonafewmoveslaterthegame.

rnq2rk1/1p1pbppp/4pn2/4N3/1PP5/2Q1B3/4PPPP/2R1KB1RbK-016Jonnycontinuedhisaimtoachievethefirstplace.ItplayedverywellagainstZigguratthatwasoutofbookafter11.Nd2.Jonnyhadtwomorebookmoves,namelyupto13.…b5.Thentheplayersstartedtheirowngame.Jonnydecidedtosacrificetemporarilyapawnonc4withascompensation,mobility,initiativeandpressure.Itledtoadynamicgamewithopticallychancesatbothsides.StillJonnyturnedouttobethemoredeeplylookingprogram.Inthediagrampositionitplayed37.d5.SimplecapturewouldgiveJonnyasuperiorpositionwithtwobishopsandapassedpawn.Howeverblackbelievedithadacountertrickbysacrificingtheexchangeandobtainingtwopassedpawnsinthecenter.Seediagram.

6k1/p2nb1pp/4p3/P1p1Pp1P/2RP1P2/6P1/5KB1/1r2B3w--037

6k1/p2nb1pp/8/P1ppPp1P/2R2P2/6P1/6K1/4B3w--040Obviouslyblackhadhighexpectationsofthepoweritspawns.StillJonny’sevaluationmusthavebeenbetterbecauseblackhasnochanceatallinthecurrentposition.Jonnyhandleditprofessionallyandachievedafullpointwithconvincingplay.Thestrategiclinewasbringingthewhiterooktotheseventhrank,bringingdeathanddestruction.Aclearwinforwhite.Chiron–ShredderwasaSiciliangamewithwhitefianchetto.Bothprogramsplayedalongwell-knownpathsoriginatingdirectlyfromtheiropeningbook.AfarreachingstrategicdecisionwasmadebyShredderbyplaying25.…f4weakeninginessencethewhiteking’sposition.Seediagram1below.

Diagram1

r4rk1/2qb2pn/1p1p4/p2Ppp1p/2P5/Q4NPP/PP3PB1/2R1R1K1b--325

Howeverwhitewasnotawaitingthestrategicpressureasblackmightforeseeanddecidedtotaketheinitiativebyplaying26.gxf4,Rxf427.Nxe5.Itbroughttolightpossibilitiesliked6andopeningthelongdiagonaluptoa8.Meanwhilewhiteenrichedthepossibilitiesbyinsertingtheadvanceofthec-pawn.Afterthecapturesblack’spawnpositionwascompletelyshattered(seediagram2).Whitemayhaveevaluatedthispositionasbettersinceitisabletocollectthreeweakpawns:32.Rxe5,Rh433.Qxc5,Nf634.Qxa5.

Diagram2

q6k/3b2pn/3P4/p1p1p2p/5r2/Q6P/PP3P2/2R1R1K1w--032Yetitwasdifficulttogainadvantagefrommateriallyfavourableposition,sincethedynamicofthetwoblacklightpiecesandtheweakeningofthewhitekingfortressshowedtobesufficientcompensationforblack.Whatfollowsisanexcitingbattleunderspeedchessconditionssincebothplayerswereinthelastquarterofthetimeallotted.Finally,theyarrivedinthepositionofdiagram3.

Diagram3

7k/2Rb2p1/5n2/7p/1q5r/6QP/PP3P2/4R1K1w--641Therewhitedecidedtoexchangetherooksviaanindirectmethodbyplaying41.Re7,Qxe742.Qxh4.Theresultingpositionwasthestartofafascinatingendgameinwhichsubtlemaneuversfinallydecidedthewinner.

Diagram4

8/6pk/6b1/7p/3n1Q1P/5P2/4qRK1/8b--2779Diagram4showsoneofthesubtletiesplayedsinceblackkepttheinitiativebyplaying79.…Ne6.Subsequentlyblackcontinuedtogainspatialadvantageandwithsimplebutnicecombinationittransformedthegameintoawin.

After6roundsShredderdeservedlyleadsthepackby4.5outof5.FollowedbyJonny4outof5andKomodo3.5outof5.ThelastroundwillbringthedecisionsinceShredder(white)ispairedtoJonny.

Round7 Shredder–Jonny½-½ TheBaron–Chiron½-½ Komodo–ChessEbbiz91-0 Ziggurat-byeTheWorldComputerSoftwareChampionshiphadtobedecidedinthelastroundinthegameShredder–Jonny.BothprogrammersknoweachotherverywellbutafriendlydrawwasnottobeexpectedsincethatwouldmeanthatShreddergainedthetitle.Theirfightwasofthehighestcaliber,excitingwithsacrificesfrombothsidesandwithsubtlemaneuvers.Belowweprovidefourhighpointsofthecontestwhichfinallyendedinadraw.OurcongratulationsarethereforeforStefanMeyer-KahlenforShreddersperformanceofwinningthetournamentwith5pointsoutof6games.Afantasticresult.AfteraquietSemi-Slavopeninginwhichbothsidesfollowedthebooklinesuptofarinthemiddlegame,therealstruggleshowedmanysubtleties.Inthediagrambelowweseethatwhiteisconfrontedwithablackknightcapturingpawnh3.Thereactionisdenyingtheknightandlookingforownopportunitiesby42.Qa5.

1br3k1/1b6/p3qp2/1p4pp/3BP3/5N1n/1P3PP1/1B1RQ2Kw--042Afterwhitehascapturedtheknightonh3,blackhasmaneuvereditspiecesonsuchpositionsthathecouldimmediatelyregainthepiecebyanicecombination,namely47.…Rxb148.Rxb1Qxe449.Rf1(49.Rd1isansweredby49.…g4)Qxd450.Qxh5,Qe4.

1b6/1b4k1/p4p2/1p4pp/3BPq2/7Q/1P3PPN/1Br3RKb--247Withtwobishopsandfourpawnsagainstrookandknightwiththreepawnsthereisakindofmaterialbalance,butpositionalthesituationisratherdynamic.Anexampleisseeninthediagram4whereblackplayed58.…Bc5.Thegamecontinuedby59.Nxb5,Bxf260.Kxf2,Qxb561.Qd4.Inthefollowingitturnedoutthatbothsideshadsufficientresourcestokeepthedelicatebalanceasitis.

8/1b6/3b1pk1/pp2q1p1/3N2Q1/8/1P3PP1/3R2K1b--758Asecondexampleofdelicatebalanceisgivenindiagram5wherethegamecontinuedby84.Qd4,Qxb385.Rxg5+,Kf786.Qa7+,Ke8.

1q6/6k1/4bp2/R5p1/8/1P1Q4/6P1/7Kw--384Afterexchangingthequeens,thefinalresultwasadrawaccordingtothe6-menendgamedatabasetableKRPKBP.OncemorecongratulationstoShredder.InthegameTheBaronversusChiron,TheBaronshoweditspowerasbeingadangerousprogramforstrongcontenders.Itlefttheopeningphasewithasmalladvantage,apawnupwithsomeobstaclestoovercome.Howeverblackshowedthattheobstacleswereabletohelphimtoregainthepawn.Thereafteritwasadraw.AremarkablegamewasplayedbyKomodoandChessEbbiz9.KomodowonbytimeforfeitatthesideofChessEbbiz9.InthefinalpositionKomodowaswinning.ItbroughtKomodoonthesharedsecondplacetogetherwithJonny.

Play-offForthesecondandthirdplaceaplay-offwasnecessarybetweenJonnyandKomodo.Twogameswiththetimecontrolof20minutesand15secondspermovewillbeplayed.ThefirstgamewasaQueensPawnopening.Bothplayersfollowedtroddenpathsandarrivedinanequalmiddlegame.Manypieceswereexchangedandonlyafewremainedontheboard.Howeverallpawnsremainedontheboardandsoontheywerepositionedinsuchawaythatthereweretwowallswhichwereintermingledalthoughinthemeantimewhitehadsacrificedapawn.Bothplayerscontinuedtomovethepiecesforwardsandbackwards,leftwardsandrightwards.After170movestheystoppedplayingandagreedonadraw.ThesecondgamewaswonbyKomodo.AnattackontheblackkingsidewasnotstoppablebyJonny.After39.g5hegaveup.

Thefinalstanding1. Shredder2. Komodo3. Jonny4. Chiron5. TheBaron6. Ziggurat7. ChessEbbiz9