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Subject: Re: pmess at cct

Author: Vikrant Malvankar

Date: 20:15:50 02/27/06

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On February 27, 2006 at 10:39:25, Mridul Muralidharan wrote:

>Hi,
>
>  Here is a short writeup of the games I observed ....
>
>I seem to have unfortunately lost the logs from the first day ... so 'game
>comments' from memory.
>The tourny started in the stupidist way possible - I overslept and missed the
>first round !
>
>R1 : Pmess vs Hossa
>Forfiet. Sorry for not being able to make it Steffen - alarm clock went bonkers
>:-(
>
>R2 : Tornado vs Pmess
>Pmess playing without a book - and always falls for the stupid opening line
>(imho)
>
>1. d4 d5 2. c4 e6 3. Nc3 Bb4 4. Nf3 dxc4 5. e4 (or e3 for that matter) b5?
>
>It thinks it can retain the pawn (with slim margin of +0.1 or so) , keeps
>playing - and keeps messing up its position !
>Luckily , tornado did not convert this advantage into a win and (as you will see
>later) inspite of some bugs , pmess managed to win this one.
>
>R3 : Arasan vs Pmess
>
>Arasan has traditionally been a problem engine for most of my engines.
>I had not tested the last couple of them against it , so had no idea what to
>expect.
>It was a similar opening as r2 , and you will see the similar b5 move ... though
>I think it was not as stupid in the game as earlier on - comes sufficiently
>later to be not losing too much tempi (but it is still quite bad).
>By middle game , arasan 'owned' the center and I was expecting a crushing
>defeat.
>My suspicion about why arasan did not win this match was that it was a bit too
>protective of its king side pawns and secondly (maybe more importantly) 'cos it
>created holes in the center by pawn pushes - allowing the bishop in a6/b7 to get
>back into the game.
>According to pmess , around move 28 or so the game started slipping away from
>arasan (score became +ve for itself at around that time).
>[D]rr6/1bp3qk/1n2pn1p/5p2/2pP1P2/B1P2N2/4B1PP/1RQ2RK1 w - - 0 29
>As you can see here , pmess has a lousy pawn structure - a definition of why you
>need good pawn structure eval code ! (I added it to my todo list to revamp that
>code :-) ).
>A really tense game - once again highlighting the 'need' for a opening book.
>
>Another interesting position is this one -
>[D]rr6/2p4k/4p2p/3n1p2/2pPbPq1/B1P5/1R4PP/2Q1NRK1 b - - 0 33
>pmess failed high on Rxa3 (it was thinking of Rg8 until then).
>
>All in all , a tough fight against a tough opponent.
>
>R4 : Pmess vs Chepla
>
>I have been playing some sparring matches against chepla before cct and result
>has been roughly equal (with chepla with its monster nps having a lead :-) ).
>Chepla gets insane depths and nps ... though Riverman slowed it down with added
>mobility seeing the way it was playing pre-cct (damn me for pointing this to him
>:-) ).
>AND , this was the first game where a severe bug finally decided to rear its
>head.
>The opening was , surprisingly , not too bad for pmess imo (and I am a patzer ,
>so dont take my word for this) ... and into the middle game , like Riverman put
>it , "pmess owned the center , the king side and the queen side" :-P ofcourse he
>was jesting :)
>Which is when pmess decided to trade rook for a bishop ... I did fix a bug there
>afterwards , but that was not severe enough a problem I guess.
>But yes , this was the begining of the downfall for pmess ... from then on , the
>score never really went up.
>It was a tough seesaw since ... with chepla and pmess alternating in some
>maneuvering for control. The e file was a monster for chepla and eventually won
>the game for it.
>[D]5rk1/1p2q2p/2ppr3/p4pp1/2PQ4/P1N3P1/1P5P/3R1B1K w - - 0 28
>According to chepla , this was the begining of the end for pmess ... I did find
>a pretty severe bug in my queen eval - and the result was Qa7 here ... but I am
>not fully convinced that this was a fatal mistake.
>But the resulting moves were definitely impacted by the bug ... not sure which
>move had a spike in score fall , but it was a steady decline.
>A well deserved win for chepla and spanks for pmess :-)
>
>r5: Postmodernist vs Pmess
>This game , by far , had the most severe bug in the whole tourny for pmess.
>A crushing kingsafety eval bug which increased the eval by more than a pawn
>(more in some others) !
>As can be expected , pmess lost !
>The relevent position where this is most clearly reflected in the static eval
>would be this position (from game) :
>[D]5rk1/pp1b1ppp/8/q2n2B1/2Q2p2/b1PB4/P1PK2PP/1R2R3 b - - 0 17
>pmess evaluated this as 1.5 in blacks favour ! (after fixing , about 0.4 - 0.5
>in blacks favour).
>This was clearly reflected in the score's of postmoderninst and pmess in the
>game - until pmess began to 'lose' it , the difference was as high as 1 pawn !
>As Andrew put it , "Postmodernist is getting bored of pmess's attack" :-)
>
>After an exhausting first day of cct (ya , I stayed up the whole 5 rounds, and I
>am in India !) , no sleep for the 'bugged' , I was sitting and fixing my bugs
>for the next 3 hours.
>I ifdef'ed all my changes (#ifdef CCT_DAY1_CHANGES) so that in case I break
>something , I can always recompile with this flag removed :-)
>Luckily , it seems that I can code for 36 hours straight ... so nothing broke
>:-D
>Revamped kingsafety totally , changed some passer eval code (I suspect this was
>not that well tested :-( ... see the chessthinkerx game for more comments) and
>the center control code - that arasan game was scary !
>
>Considering that I had work deliverables also to complete , cct was really
>stretching my time, but made it to day 2 without too much problems ... and no r6
>forfiet from me :-)
>
>R6 Tinker vs Pmess
>I cobbled up a book from some pgn's lying around to not lose too much time in
>the opening ... and what a blunder that was :-(
>Came off almost a pawn down from the opening itself ... rest of the match was
>one looong struggle to overcome this severe handicap.
>I think tinker might have some bugs with draw detection ... since quite a few
>times in the game , it was allowing repetition for pmess inspite of showing +ve
>eval for itself.
>This match ended in a draw.
>
>R7 Pmess vs Thinker
>I promptly kicked out the book before this match :-)
>I prefer loss due to my messup's than some random pgn book move issues !
>This was a surprising game in many ways since I expected to be crushed.
>As soon as I saw the pairings , I remember asking Peter whether it was for real
>- chessthinker was way too strong to face pmess after it has lost like 3 matches
>!
>I am still analyzing this game , but my impression while watching this game was
>that thinker won due to superior endgame knowledge (this is pathetically low in
>pmess) ... pmess was a pawn up till the late-middlegame before I left for
>dinner. Came back to find a loss - ah well , better a 'fixable' endgame loss
>than a more tougher middle game crush :-)
>
>R8 Pmess vs K9
>I really cant do justice to this game - I slept off after starting the game.
>Woke up around 1.5 hours later to find a win ...
>When going through the game later , I found a very strong king side attack by
>pmess that lead to a won rooks vs queen endgame.
>
>R9 Prophet vs Pmess
>
>Same as R8 for this game too ... 6 hours of sleep in 3 days was begining to show
>and I slept off after starting this game too (more on that below).
>Pmess seemed to have let its queen get 'trapped' in the wrong side of the board
>for quite sometime until this position
>[D]5r2/p2b2pk/1pn1p2p/3pP1p1/P1pP4/2P1NrP1/1qPBQP1P/R4RK1 b - - 0 33
>where it play Nxd4
>It was not a staight win after this move though.
>Pmess tried to force a draw by 3rep at around move 50 or so, but prophet will
>not play ball !
>[D]8/R1B3pk/1p4bp/3pp1p1/8/2P1r1Pq/2QNrP1P/5RK1 w - - 0 53
>It played Qc1 and pmess eval kept rising since them.
>I think prophet might have played some bad moves since that (time pressure ?) ,
>the game was over in about 3 moves hence (pmess announced mate score).
>
>
>I continued to sleep , unaware of what happened in R9 ... and since that was the
>last game of the tourny , I did not keep an alarm - but an IM from a friend woke
>me up later, and I find that there is a new tourny about to begin : I dont think
>this 'cct blitz' was announced earlier on.
>Note - it was about to begin : lot of games were not yet started.
>Asked peter if I could join and he flat out refused saying it was 'too late'.
>Oh well , pmess usually sucks at blitz and might have got crushed anyway :-)
>
>Said goodbye and dragged myself to the bed to get some much needed sleep !
>Thanks to all at CCT , was great fun - as always :-) The discussions on 64 were
>enlightening , and I think we taught erdo how to use the cli quite well ;-)
>
>What I learned from it ?
>* Keep alarms properly , and use two alarm clocks for reduncency !
>* Parallel search worked beautifully , my tests on the pgn later on showed a
>consistent speedup of >= 1.87 (worst was 1.87)
>* My eval approach is not too bad , just buggy like hell :-)
>* Move ordering stats were pretty good.
>* Sleep better the day before the tourny - similar to how you prepare for an
>exam I guess.
>
>
>Thanks,
>Mridul
>
>PS : A bit too long post , should have posted in some site I guess ....


Mridul All the Best for great future.

Finally there is someone from India who has taken Chess Programming
Seriously.(Considering that such a big IT Nation that India is)



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