Testing with this position (Best move Rxg5!)
[D]8/8/4kpP1/4p1n1/4K3/3P2R1/8/8 w - - 0 1
I had these results. Looks like it is most convenient to probe the tablebases when the depth remaining is more than 2. It does not diminish the node rate and there is a clear benefit. The efficiency of hits of the table base cache is about 80%.
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Probing Rate Solution
depth knps ply time (s)
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all 167 8 0.3
>1 355 9 0.9
>2 568 10 0.8
>3 564 11 2.7
>4 564 12 5.6
None 614 16 476.3
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I guess this must have been thoroughly tested with Nalimov's tables. Note that mine are not compressed (at least yet, I am not sure it is worth the trouble for speed purposes).
When the probing depth is > 2 the output Gaviota has is at the end.
The solution is tricky and very instructive 1. Rxg5 fxg5 2. g7 Kf7 3. Kf5! Kg8! 4. Kg4!! Kf7 5. Kxg5 e4! 6. Kh6! exd3 7. Kh7 and white wins.
if 3 ... Kxg7 4. Kxg5 wins easily
if 4. Kxg5 Kxg7 is a draw
if 6. dxe4 Kxg7 is a draw
Without 1. Rxg5 is hard to see a win for white, and it most likely is a draw after the g6 pawn falls (Ke7-Kf8-Kg7).
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2 1 0.0 +0.23 1.Rxg5 fxg5
3 1 0.0 +1.73 1.Ke3
3 1: 0.0 +1.73 1.Ke3
35 2 0.0 +1.96 1.Ke3 Ke7
62 2: 0.0 +1.96 1.Ke3 Ke7
197 3 0.0 +1.82 1.Ke3 Ke7 2.Rg2
268 3: 0.0 +1.82 1.Ke3 Ke7 2.Rg2
652 4 0.0 +1.68 1.Ke3 Ke7 2.Rg2 Kf8
780 4: 0.0 +1.68 1.Ke3 Ke7 2.Rg2 Kf8
2423 5 0.0 +1.88 1.Ke3 Ke7 2.Rg2 Ke6 3.Rf2
2759 5: 0.0 +1.88 1.Ke3 Ke7 2.Rg2 Ke6 3.Rf2
7141 6 0.0 +2.03 1.Ke3 Ke7 2.Rg2 Ke6 3.Rg1 Ke7
7682 6: 0.0 +2.03 1.Ke3 Ke7 2.Rg2 Ke6 3.Rg1 Ke7
24661 7 0.0 +1.75 1.Ke3 Ke7 2.Rg4 Kf8 3.d4 exd4+ 4.Rxd4
Ne6
25387 7: 0.1 +1.75 1.Ke3 Ke7 2.Rg4 Kf8 3.d4 exd4+ 4.Rxd4
Ne6
33010 8 0.1 :-( 1.Ke3
34195 8 0.1 :-(
73631 8 0.1 +1.01 1.Ke3 Ke7 2.d4 exd4+ 3.Kf4 Kf8 4.Kf5
Kg7 5.Rb3
74229 8: 0.1 +1.01 1.Ke3 Ke7 2.d4 exd4+ 3.Kf4 Kf8 4.Kf5
Kg7 5.Rb3
158161 9 0.3 +1.30 1.Ke3 Ke7 2.d4 exd4+ 3.Kf4 Kf8 4.Ra3
Ke7 5.Ra7+ Ke6 6.g7 Nh3+ 7.Ke4
163879 9: 0.4 +1.30 1.Ke3 Ke7 2.d4 exd4+ 3.Kf4 Kf8 4.Ra3
Ke7 5.Ra7+ Ke6 6.g7 Nh3+ 7.Ke4
372703 10 0.8 +1.66 1.Ke3 Ke7 2.d4 exd4+ 3.Kf4 Ne6+ 4.Kf5
Ng7+ 5.Ke4 Kd6 6.Rf3 f5+ 7.Kxd4 Ne6+
8.Ke3
381458 10 0.8 :-) 1.Rxg5
381912 10 0.8 :-) 1.Rxg5
382371 10 0.8 :-) 1.Rxg5
668535 10 1.4 :-) 1.Rxg5
671883 10 1.4 +Mat_24 1.Rxg5 fxg5 2.g7 Kf7 3.Kf5 Kg8 4.Kg4
Kf7 5.Kxg5 <EMPTY> <=TRANS
671885 10: 1.4 +Mat_24 1.Rxg5 fxg5 2.g7 Kf7 3.Kf5 Kg8 4.Kg4
Kf7 5.Kxg5 <EMPTY> <=TRANS
671891 11 1.4 +Mat_24 1.Rxg5 fxg5 2.g7 <=TRANS
754371 11: 1.5 +Mat_24 1.Rxg5 fxg5 2.g7 <=TRANS
754377 12 1.5 +Mat_24 1.Rxg5 fxg5 2.g7 <=TRANS
938202 12: 1.8 +Mat_24 1.Rxg5 fxg5 2.g7 <=TRANS
938208 13 1.8 +Mat_24 1.Rxg5 fxg5 2.g7 <=TRANS
1518511 13: 2.8 +Mat_24 1.Rxg5 fxg5 2.g7 <=TRANS
1518517 14 2.8 +Mat_24 1.Rxg5 fxg5 2.g7 <=TRANS
3071098 14: 5.3 +Mat_24 1.Rxg5 fxg5 2.g7 <=TRANS
3071104 15 5.3 +Mat_24 1.Rxg5 fxg5 2.g7 <=TRANS