[r-t] Bobs only Erin Triples (was: Composition search)

[Richard Smith]

Alan Burlison wrote:

> On 25/11/2015 15:06, John Harrison wrote:
>
>> There's an anomalous looking plot of ~97% at a depth of 27.5.  Is that
>> real?
>
> I think it's the graph key, this looks like it might have come out of 
> gnuplot.

Yes, I used gnuplot to plot the data.  I've just continued 
it on to depth 35 (and removed the key).  The raw data is 
given below.  The first figure is the length, the second is 
the number of true touches.

I didn't do anything sophisticated to find this: no 
rotational pruning, no parallelisation, no hand-written 
assembler, just the C++ code I gave earlier.  The search to 
depth 35 evaluated 15.9 billion nodes in 201 seconds, or 
12.7 ns / node.  I ran it on my laptop which has a 1.9 GHz 
processor, so that works out at 24 clock cycles per node.

RAS


1	2
2	4
3	8
4	16
5	32
6	62
7	122
8	236
9	456
10	878
11	1668
12	3188
13	6092
14	11640
15	22206
16	42234
17	80318
18	152692
19	289864
20	550118
21	1042604
22	1974914
23	3737844
24	7068528
25	13357312
26	25216576
27	47577386
28	89697668
29	168973506
30	318059706
31	598167662
32	1124133852
33	2110893402
34	3960591668
35	7425076460