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Subject: Re: Question for Ed about Bishop pair.

Author: Ed Schröder

Date: 14:37:47 11/04/03

Go up one level in this thread


On November 04, 2003 at 16:39:38, Eelco de Groot wrote:

>Hello Ed, in case you are wandering by here in this forum, I had a "little"
>question about Rebel's parameters? I was looking at the Ruffian - Rebel game
>again and was wondering why actually Rebel wanted to play the move 11...Bf5.

Hard to say, I feel not qualified enough to judge between 11..Bf5 and castling
later and direct castling. What I can say Rebel played the tournament with
experimental settings which weren't exactly the best.

There will be an engine update soon (together with some bug-fixes) that after
some times comes up with Jeroen's wished move but looking at the minor
differences in score it is not very convincing :)

My best,

Ed

=========================


 [Event "?"]
 [Site "?"]
 [Date "2003.11.04"]
 [White "?"]
 [Black "?"]
 [Result "*"]

 1.Nf3 Nc6 2.e4 e5 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.Bd5
 Nxd5 9.exd5 Nb4 10.d4 e4 11.Rxe4

 r1bqk2r/2p1bppp/p2p4/1p1P4/1n1PR3/5N2/PPP2PPP/RNBQ2K1 b kq -

 00:00:00   1.00  -0.57  11..O-O
 00:00:00   1.04  -0.00  11..Nxd5
 00:00:00   2.00  -0.13  11..Nxd5 12.Qe2
 00:00:00   2.02  -0.13  11..Bf5
 00:00:00   2.02  0.16  11..Bf5 12.Re2 Nxd5
 00:00:00   3.00  0.16  11..Bf5 12.Re2 Nxd5
 00:00:00   4.00  0.00  11..Bf5 12.Re2 Nxd5 13.Ng5
 00:00:00   4.01  0.06  11..Nxd5 12.Ng5 O-O 13.Qh5
 00:00:00   5.00  0.20  11..Nxd5 12.Nc3 Nxc3 13.bxc3 Bf5 14.Re1
 00:00:00   5.01  0.20  11..Bf5 12.Re2 Nxd5 13.c4 bxc4 14.Qa4
 00:00:00   6.00  0.20  11..Bf5 12.Re2 Nxd5 13.c4 bxc4 14.Qa4 Qd7
 00:00:00   7.00  0.20  11..Bf5 12.Re2 Nxd5 13.c4 bxc4 14.Qa4 Qd7 15.Qxc4
 00:00:00   7.01  0.21  11..Nxd5 12.Ng5 Bf5 13.Re1 c6 14.Qf3 Qa5
 00:00:01   8.00  0.16  11..Nxd5 12.Ng5 Nf6 13.Re1 h6 14.Qf3 d5 15.Nh3
 00:00:01   8.01  0.20  11..Bf5 12.Re2 Nxd5 13.c4 bxc4 14.Qa4 Qd7 15.Qxc4
 00:00:01   9.00  0.32  11..Bf5 12.Re2 Nxd5 13.Qe1 c5 14.Bg5 Be6 15.Bxe7
                        Nxe7
 00:00:02  10.00  0.35  11..Bf5 12.Re2 Nxd5 13.Qe1 O-O 14.Nc3 Nxc3
                        15.Qxc3 Bf6 16.Bf4 c5
 00:00:04  11.00  0.37  11..Bf5 12.Re2 Nxd5 13.Nc3 Nxc3 14.bxc3 O-O
                        15.d5 Bf6
 00:00:07  12.00  0.36  11..Bf5 12.Re2 Nxd5 13.Bd2 Bg4 14.Qe1 O-O 15.Nc3
                        Nxc3 16.Rxe7 Be6
 00:00:15  13.00  0.35  11..Bf5 12.Re2 Nxd5 13.Bd2 O-O 14.Nc3 Be6 15.a4
                        c5 16.axb5 Nxc3 17.Bxc3 axb5 18.Rxa8 Qxa8 19.Qd3
 00:00:36  14.00  0.32  11..Bf5 12.Re2 Nxd5 13.Bg5 f6 14.Bd2 O-O 15.Re1
                        Qd7 16.Nc3 Nxc3 17.Bxc3 d5 18.Ba5
 00:01:38  14.01  0.32  11..Nxd5 12.Bg5 O-O 13.Bxe7 Nxe7 14.Re1 Nd5
                        15.Qd3 Bb7 16.Nbd2 f5
 00:01:48  14.07  0.34  11..O-O 12.Nc3 Bb7 13.Re1 Nxd5 14.Nxd5 Bxd5
                        15.Bf4 Bf6 16.Qd3 Bxf3 17.gxf3 Bg5
 00:02:19  15.00  0.39  11..O-O 12.Nc3 Bb7 13.Re1 Nxd5 14.Nxd5 Bxd5
                        15.Qd3 f5 16.Bf4
 00:04:06  16.00  0.41  11..O-O 12.Nc3 Bb7 13.Re1 Nxd5 14.Nxd5 Bxd5
                        15.Qd3 Bf6 16.a4 Re8 17.Rxe8
============

>[D]r1bqk2r/2p1bppp/p2p4/1p1P4/1n1PR3/5N2/PPP2PPP/RNBQ2K1 b kq - 0 1
>
>Not that 11...Bf5 is an obviously bad move but as Jeroen Noomen pointed out
>11...0-0 would have been better. Now my reasoning was that, if I increased the
>value for the Bishop pair, maybe I'd see that the score for 11...Bf5 would go
>down, since White can exchange Bishops after 11...Bf5 12.Re2 Nxd5 13.Bg5 O-O.
>
>Black can choose to play 13...f6 instead but that does not seem a good move
>either. If 13...f6 is the move Rebel expects to play, and that is the reason why
>increasing [Bishop Pair] does not work, this does not seem good either since
>this move weakens the pawn structure much and with short castling still an
>option it seems that it is also bad because of King Safety? Or it should be?
>Black has already compromised the pawn structure on the Queen side and with f6
>so early in the game would weaken its pawns also on the King side. It just seems
>almost fatal to do this on both sides especially early in the game, only to gain
>a tempo or two (White's R back to e2 and B to d2). Also mobility of its own
>Bishop on e7 is decreased by playing f6.
>
>I experimented with different values for the Bishop pair but almost the only
>effect I saw seemed to be that 13.Bd2 was chosen more than 13.Bg5, the opposite
>of what I'd expect. The scores did not change noticeably, even with maximum
>value of 500. So I was wondering if something could be broken here, almost as if
>a plus changed into a minus or something?
>
>Most Rebel versions I tried only want to play Bf5, except Thorsten's settings
>which I don't know and also one Betazoid version where I put in [Bishop Mobility
>= 60]. Another possibility I thought of that it could have something to do with
>that new parameter, that is if really something might be broken?
>
>These were the different results:
>
>[Event "23rd DOCC"]
>[Site "Leiden NED"]
>[Date "25/10/2003"]
>[Round "07"]
>[White "Ruffian"]
>[Black "Rebel"]
>[Result "1-0"]
>[Opening "C88 Ruy Lopez: Closed"]
>
>1. Nf3 Nc6 2. e4 e5 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. Bd5
>Nxd5 9. exd5
>Nb4 10. d4 e4 11. Rxe4 Bf5 12. Re2 Nxd5 13. Bg5 O-O 14. Bxe7 Nxe7 15. Nc3 b4 16.
>Ne4 Nd5
>17. a3 Bg4 18. Re1 Re8 19. Qd3 Bf5 20. Nfd2 Nb6 21. Qf3 Bg6 22. axb4 d5 23. Nc5
>Rxe1+
>24. Rxe1 Bxc2 25. Qe2 Qd6 26. Nxa6 f6 27. b5 Bf5 28. Nf1 Bd7 29. Ne3 Re8 30. Qc2
>Nc4 31. b3
>Nxe3 32. Rxe3 Ra8 33. g3 Ra7 34. Qe2 f5 35. Kg2 h6 36. Nc5 f4 37. Re7 Bxb5 38.
>Qe6+ Qxe6
>39. Nxe6 Kh8 40. Rxc7 Ra3 41. Nxf4 Rxb3 42. Nxd5 Rd3 43. Nc3 Bd7 44. Rxd7 Rxc3
>45. h4
>Kg8 46. f3 Rc2+ 47. Kh3 h5 48. g4 Kh7 49. gxh5 Kh6 50. Kg4 Rg2+ 51. Kf5 Kxh5 52.
>d5 Rd2
>53. Rd8 Kxh4 54. d6 1-0
>
>
>After 11.Rxe4, diagram see above
>
>r1bqk2r/2p1bppp/p2p4/1p1P4/1n1PR3/5N2/PPP2PPP/RNBQ2K1 b kq - 0 1
>
>Tg3b3 with [Bishop Pair = 500]
>
>00:00:02.8	-0,75	1	4	O-O
>00:00:02.9	-0,15	1	12	Nxd5
>00:00:02.9	-0,31	2	166	Nxd5 Qe2
>00:00:02.9	-0,31	2	431	Bf5
>00:00:02.9	0,10	2	531	Bf5 Re2 Nxd5
>00:00:03.1	0,10	3	892	Bf5 Re2 Nxd5
>00:00:03.2	-0,05	4	2865	Bf5 Re2 Nxd5 Ng5
>00:00:03.3	0,00	4	7238	Nxd5 Ng5 O-O Qh5
>00:00:03.7	0,02	5	18689	Nxd5 Ng5 Nf6 Qf3 O-O
>00:00:03.7	0,02	5	20944	Bf5
>00:00:03.7	0,18	5	21625	Bf5 Re2 Nxd5 Nc3 Nxc3 bxc3
>00:00:04.0	0,21	6	33068	Bf5 Re2 Nxd5 c4 bxc4 Qa4+ Kf8
>00:00:04.9	0,21	7	84244	Bf5 Re2 Nxd5 c4 bxc4 Qa4+ Kf8 Qxc4
>00:00:06.7	0,21	8	210420	Bf5 Re2 Nxd5 c4 bxc4 Qa4+ Kf8 Qxc4
>00:00:12.4	0,23	9	681436	Bf5 Re2 Nxd5 Qe1 Be6 Nc3 Nxc3 Qxc3 O-O Bf4
>00:00:25.1	0,41	10	1823275	Bf5 Re2 Nxd5 Bd2 O-O Nc3 Nxc3 Bxc3 Bf6 Ba5
>00:00:49.9	0,40	11	4317423	Bf5 Re2 Nxd5 Bd2 O-O Nc3 Nf6 a4 b4 Na2 c5
>00:01:55.5	0,39	12	10731482	Bf5 Re2 Nxd5 Bd2 O-O Nc3 Nb4 Ne1 Re8
>00:05:08.5	0,37	13	29566029	Bf5 Re2 Nxd5 Bd2
>00:13:28.1	0,36	14	91594057	Bf5 Re2 Nxd5 Bg5 O-O Bxe7
>(Move: Bf5  (1/28)  depth=15)
>
>Betazoid Tg3b2 with [Bishop Pair = 300]
>
>00:00:01.8	-0,75	1	4	O-O
>00:00:01.9	-0,15	1	12	Nxd5
>00:00:01.9	-0,31	2	166	Nxd5 Qe2
>00:00:01.9	-0,31	2	431	Bf5
>00:00:01.9	0,10	2	531	Bf5 Re2 Nxd5
>00:00:02.1	0,10	3	892	Bf5 Re2 Nxd5
>00:00:02.2	-0,05	4	2865	Bf5 Re2 Nxd5 Ng5
>00:00:02.2	0,00	4	7238	Nxd5 Ng5 O-O Qh5
>00:00:02.4	0,02	5	18687	Nxd5 Ng5 Nf6 Qf3 O-O
>00:00:02.4	0,02	5	20925	Bf5
>00:00:02.5	0,18	5	21666	Bf5 Re2 Nxd5 Nc3 Nxc3 bxc3
>00:00:02.8	0,21	6	33077	Bf5 Re2 Nxd5 c4 bxc4 Qa4+ Kf8
>00:00:03.2	0,21	7	84260	Bf5 Re2 Nxd5 c4 bxc4 Qa4+ Kf8 Qxc4
>00:00:04.2	0,21	8	209791	Bf5 Re2 Nxd5 c4 bxc4 Qa4+ Kf8 Qxc4
>00:00:07.3	0,23	9	680435	Bf5 Re2 Nxd5 Qe1 Be6 Nc3 Nxc3 Qxc3 O-O Bf4
>00:00:14.7	0,41	10	1873558	Bf5 Re2 Nxd5 Bd2 O-O Nc3 Nxc3 Bxc3 Bf6 Ba5
>00:00:28.3	0,40	11	4355651	Bf5 Re2 Nxd5 Bd2 O-O Nc3 Nf6 a4 b4 Na2 c5
>00:01:04.0	0,39	12	11027147	Bf5 Re2 Nxd5 Bd2 O-O Nc3 Nb4 Ne1 Re8
>00:02:49.0	0,35	13	30278902	Bf5 Re2 Nxd5 Bg5 O-O Bxe7 Nxe7 Nc3 Re8 Qd2 b4 Ne4
>Bxe4
>00:07:48.2	0,36	14	86059358	Bf5 Re2 Nxd5 Bg5
>00:29:40.2	0,37	15	327255945	Bf5 Re2 Nxd5 Bg5 f6 Bd2 O-O
>(Move: Bf5  (1/28)  depth=16)
>
>Tg3b met [Bishop Pair = 150]
>
>00:00:03.3	-0,79	1	4	O-O
>00:00:03.4	-0,19	1	12	Nxd5
>00:00:03.4	-0,35	2	166	Nxd5 Qe2
>00:00:03.4	-0,35	2	431	Bf5
>00:00:03.5	0,05	2	531	Bf5 Re2 Nxd5
>00:00:03.6	0,05	3	892	Bf5 Re2 Nxd5
>00:00:03.7	-0,09	4	2867	Bf5 Re2 Nxd5 Ng5
>00:00:03.8	-0,04	4	7435	Nxd5 Ng5 O-O Qh5
>00:00:04.1	-0,01	5	18542	Nxd5 Ng5 Nf6 Qf3 O-O
>00:00:04.1	-0,01	5	20795	Bf5
>00:00:04.1	0,14	5	21477	Bf5 Re2 Nxd5 Nc3 Nxc3 bxc3
>00:00:04.4	0,16	6	32741	Bf5 Re2 Nxd5 c4 bxc4 Qa4+ Kf8
>00:00:05.4	0,16	7	86566	Bf5 Re2 Nxd5 c4 bxc4 Qa4+ Kf8 Qxc4
>00:00:07.2	0,16	8	230398	Bf5 Re2 Nxd5 c4 bxc4 Qa4+ Kf8 Qxc4
>00:00:13.0	0,22	9	709303	Bf5 Re2 Nxd5 Qe1 Bg4 Bg5 Bxf3 gxf3
>00:00:23.5	0,39	10	1742090	Bf5 Re2 Nxd5 Bg5 O-O Bxe7 Nxe7 a4 Bg4 Qd3
>00:00:45.1	0,33	11	3915687	Bf5 Re2 Nxd5 Bd2 Bg4 Re1 O-O Nc3
>00:01:41.5	0,33	12	9748349	Bf5 Re2 Nxd5 Bd2 O-O Nc3 Be6
>00:04:52.9	0,36	13	28715021	Bf5 Re2 Nxd5 Bd2 O-O Nc3 Be6
>00:14:31.7	0,33	14	86225488	Bf5 Re2 Nxd5 Qd2 O-O Nc3 Nxc3
>00:52:02.5	0,35	15	306228426	Bf5 Re2 Nxd5 Bg5 O-O
>
>
>
>[Personality = Betazoid Tg3b3] * testing Bishop Pair parameter, normally 100
>[Pawn Value = 100]
>[Knight Value = 101]
>[Bishop Value = 100]
>[Rook Value = 101]
>[Queen Value = 98]
>[King Safety = 150]
>[Mobility = 120]
>[Pawn Structure = 105]
>[Passed Pawns = 105]
>[Passed Pawn King Tropism = 130]
>[Traditional Isolated Pawns = 80]
>[Progressive Isolated Pawns = 125]
>[Pins = 100]
>[Bishop Pair = 500]
>[Chess Knowledge = 200]
>[Attractiveness = 135]
>[Attacking = 130]
>[Strength of Play = 100]
>[Draw Contempt Factor = 0.00]
>[Selective Search = 130]
>[Search Technique = NULLMOVE]
>[Pruning = MISC_01] * TREE: if (reduce & rd=0) goto tr76
>[Pruning ? MISC_25]
>[Pruning = MISC_37]
>[Pruning ? MISC_40]
>[Pruning = MISC_22]             * Somewhat more safe Selective Search
>[Pruning = MISC_09]
>[Pruning = MISC_10]
>[Pruning = MISC09_2.00]
>[Pruning = MISC10_4.00]
>[Pruning = MISC_12]
>[Pruning = SEX_HIST_DEPTH_9] * 4
>[Pruning = MISC_03]             * Move ordering (safe) (speedup 4%)
>[Pruning = MISC_46]
>[Pruning = M46_HASH_ON]
>[Adjusted Selectivity MIDG = 4] * Maximum selective depth (midgame)
>[Adjusted Selectivity END0 = 4] * Maximum selective depth (early endgame)
>[Adjusted Selectivity END1 = 4] * Maximum selective depth (endgame)
>[Adjusted Selectivity END2 = 3] * Maximum selective depth (simple endgame)
>[ANTI-GM = OFF]
>[EVALUATION = NORMAL]
>[Extensions (remaining)= 3]
>[Extensions (checks)= 0]
>[Extensions (captures)= 0]



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