Author: Tord Romstad
Date: 02:04:36 04/22/04
Go up one level in this thread
On April 21, 2004 at 22:23:53, Tom Likens wrote:
>> 7 >= #41 0.73 110603 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
>> Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
>> Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
>> 7 #15 1.06 172533 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
>> Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
>> Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+ Kf8 Qe7+
>> Kg8 Qxg7#
>>
>>Tord
>>
>
>Hey Tord,
>
>I've been curious about this in the past. When Gothmog announces a mate in
>at most 41, does it actually see the mate (20+ moves!!). And if not, what
>is it using to bound the mate?
Hi Tom,
Believe it or not: I have no clear idea why this happens. Perhaps it is
a result of a bug somewhere, but I haven't yet bothered to study the problem
very closely, because it apparently is not very critical.
At least I am 100% sure that Gothmog does not see any 41-move variation which
ends in a mate. The maximum search depth is only 60 plies.
FWIW, here is the detailed search output for Gothmog in this position.
A '>=' before a score means that the score is a lower bound, while '<='
means an upper bound. As you can see, the score climbs from mate in 41
to mate in 15 very quickly (less than 2000 nodes).
1 1.62 0.00 94 Rf8+ Kh7 Qg8+
2 2.16 0.00 425 Rf8+ Kh7 Qg8+ Kg6 Rf2
3 0.00 0.07 7618 Rf8+ Kh7 Qg8+ Kg6 Qe6+ Kh7
4 0.00 0.12 12331 Rf8+ Kh7 Qg8+ Kg6 Qe6+ Kh7
5 0.00 0.24 27645 Rf8+ Kh7 Qg8+ Kg6 Qe6+ Kh7
6 >= 0.00 0.24 27656 Rf8+ Kh7 Qg8+ Kg6 Qe6+ Kh7
6 >= 0.03 0.47 63834 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Ba3+ Kd8
6 >= 0.19 0.48 63883 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Ba3+ Kd8
6 <= 0.44 0.58 80306 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Ba3+ Kd8
6 <= 0.41 0.59 80682 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Ba3+ Kd8
6 <= 0.31 0.61 81238 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Ba3+ Kd8
6 <= 0.19 0.62 82200 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Ba3+ Kd8
6 0.19 0.64 82200 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Ba3+ Kd8
7 >= 0.19 0.65 82293 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Ba3+ Kd8 Qg8+
7 >= 0.22 0.66 82365 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Ba3+ Kd8 Qg8+
7 >= 0.59 0.66 82430 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Ba3+ Kd8 Qg8+
7 >= 1.09 0.66 83052 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 1.62 0.66 83419 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 2.44 0.67 84318 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 3.44 0.77 100635 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 4.44 0.79 103186 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 5.84 0.81 103882 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 7.12 0.82 103995 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 8.16 0.83 104286 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 9.22 0.85 104376 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 10.75 0.86 104620 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 11.75 0.87 105201 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 12.75 0.90 109251 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 13.75 0.92 110005 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= 14.88 0.92 110548 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #41 0.94 110603 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #39 0.94 110634 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #36 0.94 110680 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #35 0.94 110731 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #32 0.94 110763 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #31 0.94 110799 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #28 0.94 110854 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #27 0.94 110925 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #26 0.94 111081 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #25 0.96 111259 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #24 0.96 111461 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #23 0.96 111705 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #22 0.96 111955 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #21 0.97 112213 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #20 0.97 112485 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #19 0.97 112777 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #18 0.97 113099 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #17 0.97 113468 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #16 0.98 113891 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 >= #15 0.98 114327 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+
7 <= #15 1.27 172533 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+ Kf8 Qe7+
Kg8 Qxg7#
7 #15 1.28 172533 Rf8+ Kh7 Qg8+ Kg6 Rf6+ Kxf6 Qf8+ Ke6 Qe8+
Kd6 Bxe5+ Kc5 Bd4+ Kd6 Qd8+ Ke6 Qd5+ Ke7
Bc5+ Ke8 Qe6+ Kd8 Be7+ Ke8 Bf6+ Kf8 Qe7+
Kg8 Qxg7#
Tord
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