Break-in weirdness

[gunnar]

In the attached game at move 15,

C5 is the obvious move. Now GNU Go tends to prefer E2 but ignoring that move there's an interesting problem with restricted_genmove B5 C5 and how the valuation of those moves varies with level.

	0-1	2-9	10	11	12-15	16-20
C5	12.26	12.08	14.08	14.08	10.08	7.08
B5	10.59	10.42	12.42	10.42	10.42	10.42

Except for a 0.03 followup value all those scores are purely territorial values. What mainly differs above level 10 is the amount of "Erasing territory at ..." induced by the breakin code. Erased points shown in the table below:

	10	11	12-15	16-20
C5	H7, C6	H7, C6	H7, C6, B4, G7, H8, J8	H7, C6, B4, G7, H8, J8, H8, J8, B6, C7
B5	H7	H7, G7, H8, B4, J8	H7, G7, H8, B4, J8	H7, G7, H8, B4, J8

(H8 and J8 are repeated in the debug output for C5 at levels 16-20, don't know whether that indicates anything abnormal.)

So, what's going on here?

[gunnar]

Problematic game record.