Home * Engine Testing * Test-Positions * The Nolot Suite

A test-suite created by Pierre Nolot, in 1994 introduced by Marc-François Baudot [1] [2] in rec.games.chess.

Discussion and Results

The suite was widely discussed in the news groups by Feng-hsiung Hsu [3] [4], Steven Edwards [5] [6] and others.

Bruce's Analysis

Bruce Moreland made an analysis of those hard positions [7] :
The suite contains eleven positions:
Nolot #1 bm Nxh6

Nolot #2 bm Rxc5

Nolot #3 bm Nxg5
external image 1B1QR1K1%20w%20-%20-&size=medium&coord=no&cap=no&stm=no&fb=no&theme=classic&color1=E3CEAA&color2=635147&color3=000000

external image 2R5%20w%20-%20-&size=medium&coord=no&cap=no&stm=no&fb=no&theme=classic&color1=E3CEAA&color2=635147&color3=000000

external image R1BQK2R%20w%20-%20-&size=medium&coord=no&cap=no&stm=no&fb=no&theme=classic&color1=E3CEAA&color2=635147&color3=000000
This one seems to work, but I don't think that anyone has ever gotten a big score.

This one is correct, but whether or not you find it could be a matter of luck. You might start out with a negative score, but you should get a score of +3 or so if you search long enough.

I don't think that anyone has ever solved this one.

Nolot #4 bm Nxe6

Nolot #5 bm e5

Nolot #6 bm ... axb
external image R2Q1RK1%20w%20-%20-&size=medium&coord=no&cap=no&stm=no&fb=no&theme=classic&color1=E3CEAA&color2=635147&color3=000000

external image 1K3RR1%20w%20-%20-&size=medium&coord=no&cap=no&stm=no&fb=no&theme=classic&color1=E3CEAA&color2=635147&color3=000000

external image R1B2B1R%20b%20-%20-&size=medium&coord=no&cap=no&stm=no&fb=no&theme=classic&color1=E3CEAA&color2=635147&color3=000000
This one also seems to work, but I don't know that anyone has gotten a big score.

Deep Thought got > +3 in four hours. I've gotten +5 in 93 hours. So this one is correct and extremely difficult.

I don't think that anyone has ever solved this.

Nolot #7 bm Rxd8

Nolot #8 bm Bxh7

Nolot #9 bm Ng5
external image 3R2K1%20w%20-%20-&size=medium&coord=no&cap=no&stm=no&fb=no&theme=classic&color1=E3CEAA&color2=635147&color3=000000

external image R2R2K1%20w%20-%20-&size=medium&coord=no&cap=no&stm=no&fb=no&theme=classic&color1=E3CEAA&color2=635147&color3=000000

external image 2RR2K1%20w%20-%20-&size=medium&coord=no&cap=no&stm=no&fb=no&theme=classic&color1=E3CEAA&color2=635147&color3=000000
This one is hard but works. I've gotten +2 in 37 hours.

Hsu expresses doubt about this one, but mine returned a score of +1 after a day. I don't know whether the key move wins or not.

I don't think that anyone has ever found the key.

Nolot #10 bm Rxf7

Nolot #11 bm Rxh6

external image R2Q1R1K%20w%20-%20-&size=medium&coord=no&cap=no&stm=no&fb=no&theme=classic&color1=E3CEAA&color2=635147&color3=000000

external image 1K4R1%20w%20-%20-&size=medium&coord=no&cap=no&stm=no&fb=no&theme=classic&color1=E3CEAA&color2=635147&color3=000000

This one is easy. Rxf7 should come back at +1 pretty quickly. I don't know if anyone has done better than this.

This one seems to be pretty easy to find, with a draw score or a score that is a little positive or negative, depending upon the program.

So 3, 6, and 9 are monsters and remain unsolved, if they aren't actually broken.
1, 4, and 10 are solvable, but the scores haven't been convincing yet.
11 is also findable, but it seems that the best result is a draw, so don't expect a big positive score.
8 is also solvable, but it might be found due to speculation.
2, 5, and 7 are known to be findable as wins.


The Nolot Suite as EPD records:
r3qb1k/1b4p1/p2pr2p/3n4/Pnp1N1N1/6RP/1B3PP1/1B1QR1K1 w - - bm Nxh6; id "Position 1";
r4rk1/pp1n1p1p/1nqP2p1/2b1P1B1/4NQ2/1B3P2/PP2K2P/2R5 w - - bm Rxc5; id "Position 2";
r2qk2r/ppp1b1pp/2n1p3/3pP1n1/3P2b1/2PB1NN1/PP4PP/R1BQK2R w KQkq - bm Nxg5; id "Position 3";
r1b1kb1r/1p1n1ppp/p2ppn2/6BB/2qNP3/2N5/PPP2PPP/R2Q1RK1 w kq - bm Nxe6; id "Position 4";
r2qrb1k/1p1b2p1/p2ppn1p/8/3NP3/1BN5/PPP3QP/1K3RR1 w - - bm e5; id "Position 5";
rnbqk2r/1p3ppp/p7/1NpPp3/QPP1P1n1/P4N2/4KbPP/R1B2B1R b kq - bm axb5; id "Position 6";
1r1bk2r/2R2ppp/p3p3/1b2P2q/4QP2/4N3/1B4PP/3R2K1 w k - bm Rxd8+; id "Position 7";
r3rbk1/ppq2ppp/2b1pB2/8/6Q1/1P1B3P/P1P2PP1/R2R2K1 w - - bm Bxh7+; id "Position 8";
r4r1k/4bppb/2n1p2p/p1n1P3/1p1p1BNP/3P1NP1/qP2QPB1/2RR2K1 w - - bm Ng5; id "Position 9";
r1b2rk1/1p1nbppp/pq1p4/3B4/P2NP3/2N1p3/1PP3PP/R2Q1R1K w - - bm Rxf7; id "Position 10";
r1b3k1/p2p1nP1/2pqr1Rp/1p2p2P/2B1PnQ1/1P6/P1PP4/1K4R1 w - - bm Rxh6; id "Position 11";

External Links


  1. ^ 11 tactical positions computers can't solve by Marc-François Baudot, rec.games.chess, July 11, 1994
  2. ^ Pierre Nolot's solutions to the 11 positions by Marc-François Baudot, rec.games.chess, July 29, 1994
  3. ^ Nolot's 11 difficult positions (possible spoilers) by Feng-hsiung Hsu, rec.games.chess, July 29, 1994
  4. ^ A second look at the Nolot positions by Feng-hsiung Hsu, rec.games.chess August 2, 1994
  5. ^ Nolot test positions: EPD version by Steven Edwards, rec.games.chess, July 29, 1994
  6. ^ Nolot's test vs. Spector by Steven Edwards, rec.games.chess, July 29, 1994
  7. ^ The Nolot Suite analyzed by Bruce Moreland

What links here?

Up one level