user27314: In an engine match Leela zero vs Komodo 14 Dragon at hyper-long time 6 hours each engine) in an Alekhine Defense game, Modern variation, the following rook endgame appeared on the board.
[FEN "4r1k1/pp3p2/6p1/2B3K1/2P4P/8/PP3P2/6R1 b - - 0 1"]

BLACK to move. According to KOMODO 14 Dragon internal analysis the position is + 1,99 at White at depth = 49 63.2M of tablebases. Meaning that we do not know if the above position is a win or a draw. Please, someone with a software powerful enough can go deeper? Is the position above, critical for the evaluation of the Alekhine opening, a win for White or a draw?

user24511: The Position: Win or Draw
It is as Draw!
Which I am genuinely surprised about to be honest.
My initial review of the board would say that with the following; White should be winning (which they are in the starting position);

5 v 5 Pawns
1 v 1 Rook
White has a Bishop
Whites King has been engaged in the offence.

However as black has the move initiative ... they are able to slowly equalize the position.
On the Topic of Table Bases
End Game TableBases now aren't necessarily as relevant as they use to be.
Which is probably a good thing. Reasonable TableBases are rare, and more importantly they are impractical. If you have a table base of 5 pieces, if I have a table base of 6 piece end games...well, then there is no competition.
Here is where it gets tricky. How do you reasonably provide that to engine,
The Syzygy 7 Piece TableBase is 18tb , containing 4.23e14 positions. A Syzygy 8 piece TableBase (which doesn't even exist and is what is technically required for this position)  is something like 3.8e16 positions and would require probably 4.5PB of storage if not more.
Interesting Take Aways

Stockfish sees the position as a draw and equal (0.00) at move 20.

Stockfish more efficient at analyzing the position and reaching the position at a depth of of 35.

Looks like there is a new build of stockfish planned that appears to be slightly more efficient at reviewing the position.

List item



The Results
[Event "StockFish 14 Analysis of Position Depth 52 @923753 kN/s"]
[SetUp "1"]
[FEN "4r1k1/pp3p2/6p1/2B3K1/2P4P/8/PP3P2/6R1 b - - 0 1"]
[PlyCount "66"]

1... Re5+ 2. Kf4 Rxc5 3. b3 Rf5+ 4. Ke3 Re5+ 5. Kf3 Rf5+ 6. Ke2 Re5+ 7. Kf1 Kg7 8. Rg3 a6 9. Re3 Rh5 10. Ke2 Rxh4 11. Re7 b5 12. Kd3 Kf6 13. Re1 Rh5 14. Kd4 Rh4+ 15. Kd5 bxc4 16. bxc4 Rh2 17. c5 Rxf2 18. a4 Rd2+ 19. Kc6 Ra2 20. Kb6 Rxa4 $11 21. c6 Rc4 22. c7 Rc2 23. Re8 g5 24. c8=R Rxc8 25. Rxc8 g4 26. Rf8 Kf5 27. Kxa6 g3 28. Rxf7+ Kg4 29. Kb5 g2 30. Rg7+ Kf3 31. Kc5 Kf2 32. Kc4 Kf1 33. Kc5 g1=Q+ 34. Rxg1+ Kxg1

Method
Hijacked the GPU Cluster from Work (again...see the footer as to why).
Running StockFish14 as its a "neutral" engine in regards to the analysis / outcome of the game...in that it wasn't involved. It is also faster and more accurate at pruning positions that Komodo.
Also decided to run this through ChessBase to see what other folks had found.
I originally did the analysis on this but stuffed up and had as White to Move. Which was White had a forced mate sequence (Mate in 20 though)

27314: <p>In an engine match Leela zero vs Komodo 14 Dragon at hyper-long time 6 hours each engine) in an Alekhine Defense game, Modern variation, the following rook endgame appeared on the board.</p>
<pre><code>[FEN &quot;4r1k1/pp3p2/6p1/2B3K1/2P4P/8/PP3P2/6R1 b - - 0 1&quot;]
</code></pre>
<p>BLACK to move. According to KOMODO 14 Dragon internal analysis the position is + 1,99 at White at depth = 49 63.2M of tablebases. Meaning that we do not know if the above position is a win or a draw. Please, someone with a software powerful enough can go deeper? Is the position above, critical for the evaluation of the Alekhine opening, a win for White or a draw?</p>
 24511: <p><strong>The Position: Win or Draw</strong></p>
<p>It is as Draw!
Which I am genuinely surprised about to be honest.
My initial review of the board would say that with the following; White should be winning (which they are in the starting position);</p>
<ul>
<li>5 v 5 Pawns</li>
<li>1 v 1 Rook</li>
<li>White has a Bishop</li>
<li>Whites King has been engaged in the offence.</li>
</ul>
<p>However as black has the move initiative ... they are able to slowly equalize the position.</p>
<p><strong>On the Topic of Table Bases</strong></p>
<p>End Game TableBases now aren't necessarily as relevant as they use to be.
Which is probably a good thing. Reasonable TableBases are rare, and more importantly they are impractical. If you have a table base of 5 pieces, if I have a table base of 6 piece end games...well, then there is no competition.
Here is where it gets tricky. How do you reasonably provide that to engine,</p>
<p>The Syzygy 7 Piece TableBase is 18tb , containing 4.23e14 positions. A Syzygy 8 piece TableBase (<em>which doesn't even exist and is what is technically required for this position</em>)  is something like 3.8e16 positions and would require probably 4.5PB of storage if not more.</p>
<p><strong>Interesting Take Aways</strong></p>
<ul>
<li><p>Stockfish sees the position as a draw and equal (0.00) at move 20.</p>
</li>
<li><p>Stockfish more efficient at analyzing the position and reaching the position at a depth of of 35.</p>
</li>
<li><p>Looks like there is a new build of stockfish planned that appears to be slightly more efficient at reviewing the position.</p>
</li>
<li><p>List item</p>
</li>
</ul>
<p><a href="https://i.stack.imgur.com/xhuZq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xhuZq.png" alt="New Stockfish Version Confirmed???" /></a></p>
<p><strong>The Results</strong></p>
<pre><code>[Event &quot;StockFish 14 Analysis of Position Depth 52 @923753 kN/s&quot;]
[SetUp &quot;1&quot;]
[FEN &quot;4r1k1/pp3p2/6p1/2B3K1/2P4P/8/PP3P2/6R1 b - - 0 1&quot;]
[PlyCount &quot;66&quot;]

1... Re5+ 2. Kf4 Rxc5 3. b3 Rf5+ 4. Ke3 Re5+ 5. Kf3 Rf5+ 6. Ke2 Re5+ 7. Kf1 Kg7 8. Rg3 a6 9. Re3 Rh5 10. Ke2 Rxh4 11. Re7 b5 12. Kd3 Kf6 13. Re1 Rh5 14. Kd4 Rh4+ 15. Kd5 bxc4 16. bxc4 Rh2 17. c5 Rxf2 18. a4 Rd2+ 19. Kc6 Ra2 20. Kb6 Rxa4 $11 21. c6 Rc4 22. c7 Rc2 23. Re8 g5 24. c8=R Rxc8 25. Rxc8 g4 26. Rf8 Kf5 27. Kxa6 g3 28. Rxf7+ Kg4 29. Kb5 g2 30. Rg7+ Kf3 31. Kc5 Kf2 32. Kc4 Kf1 33. Kc5 g1=Q+ 34. Rxg1+ Kxg1
</code></pre>
<p><strong>Method</strong></p>
<p>Hijacked the GPU Cluster from Work (again...see the footer as to why).
Running StockFish14 as its a &quot;neutral&quot; engine in regards to the analysis / outcome of the game...in that it wasn't involved. It is also faster and more accurate at pruning positions that Komodo.</p>
<p>Also decided to run this through ChessBase to see what other folks had found.</p>
<p><em>I originally did the analysis on this but stuffed up and had as White to Move. Which was White had a forced mate sequence (Mate in 20 though)</em></p>
