Spam Log #4: SS2's Incomplete Endgame Course (Part 1)

Answer to last quiz

It’s an incorrect evaluation! In fact, white now has checkmate in 6 moves, starting with 3.Ne5. Black has to take the knight like in the Nf3 c3 example, so 3...fxe5. The key move is again 4.Qa4. No matter how black blocks the Qxd7 threat (b5/c6/Nc6), white plays 5.Qa3! threatening e7. Black again has to block the diagonal with a pawn or a knight, but no matter what black does, the next move for white is 6.Qf3, threatening f8. Black’s f-pawn is missing, the king can’t escape (if Kd7 is possible, then Qc6+ mates next move.) and the only saving move is 6...Nf5. Then after 7.Qh5 g6 8.Qg5 white mates next move because the e7 pawn and d8 queen are skewered and the king can’t move away from the e7 pawn. Black couldn’t have moved the e7 pawn on move 4 or 5 because it does not block either diagonal! (5...e6/e5 6.Qe7#) If black tries 4...Kf7 instead of blocking the diagonal, white can play 5.Qa3 threatening e7 anyway, if the diagonal is blocked, 6.Qf3+ Nf5 7.Qh5+ mates next move (black can’t block the queen invasion anymore); if 5...Kg8, 6.Qf3 is played anyway and 6...Nf5 is forced again (f8 bishop is trapped). Now 7.Qh5 threatens h7, blowing up black’s king! 7...h6 8.Qf7+ mates next move.

I agree this one is a bit tricky. In all these lines, you can stop calculating if nothing can block the queen from moving next to the king. Remember: A queen next to a king is an easy win, unless your opponent has explosion in one or the two kings can be connected in one move. The latter won’t happen in openings.

General

I’m not good at endgames myself, some endgames are very tricky. Illion has many good endgame studies and these studies explain things better than I do, make sure to check them out! Rekursiv also has a good atomic endgame book.

In atomic, the endgame phase starts after most heavy pieces are traded, like in standard chess. When you are in an endgame, the first thing to do is to count the material. Remember, in endgames, count a minor piece as one pawn. If you are down a knight for a pawn, you’re normally not down anything in the endgame. (You are worse and need to be careful but in most cases it’s a draw.) This part is about general ideas, I will talk about technical endgame positions in the next part.

Queen and rook endgames

Rook endgames are surprisingly not so common in atomic, because rooks get traded very easily. For example, whenever a rook lands on an open file, the opponent has to either trade rooks or block with a piece (or make a bigger threat). When the two rooks see each other on an open file, move the rook to the seventh rank to force a trade and gain a tempo. A rook invasion almost always guarantees a draw at least. When you are down material, keep the position complicated, always avoid trading rooks. Play for an open file and aim for a perpetual with the rook!

If you can’t stop a rook invasion, you can try two things. The first is to connect kings. Run your king towards your opponent’s king if allowed. The second is, when your are up or even in material and all your pieces are safe (in the sense that your opponent can’t use the rook to capture something resulting in a losing endgame for you), you can play for a draw by creating a 2x2 safe square for your king. Remember: the 2x2 square has to be entirely empty except your king, and none of your pieces can touch the square orthogonally. (Diagonally touching is OK) For example, if the safe square is a1, a2, b1, b2, then none of your pieces can be on a3, b3, c1 or c2. But it’s OK to have a piece on c3.

If you both have a queen, chances are you’re not in an endgame or you can trade them in a few moves. The other possibility is that you have a simple win. In endgames when few pieces are left, the queen can hardly be stopped and a queen invasion means a win in most cases. So if you have a queen and your opponent does not, chances are you can try to infiltrate your queen into their position (because, remember, this is an endgame blog so they can’t have that many pieces left to stop your queen.)

Minor piece endgames

When there are no queens or rooks on the board, the game enters the "late endgame" phase. Here are some general ideas:

1. The side with more material (pawns+pieces) is playing for a win. Pawns and pieces can be considered equal in value. If nothing is going on, being up two pawns guarantees a win. In most cases, one pawn is also a winning advantage.
2. If your opponent has exactly one bishop, keep all your pawns on opposite colored squares if possible. Don’t let the bishop attack any of your pawns. (If you are playing for a win with a bishop, take a pawn whenever you can, unless it results in a quick promotion for your opponent.)

If one side has one more bishop, but all the opponent’s pawns are on opposite colored squares (i.e. the bishop can’t attack them), and there are no pawn breakthroughs or passed pawns, the game is a draw. It’s called pawnitization and mentioned in the Rekursiv book.

3. If your opponent has a piece and you have a pawn (and in most other cases), push your pawns as far as you can. Put your king near your backward pawns, especially those blocked on the second or third rank.
4. Remember en passant exists in atomic.
5. If you are down material, trade as many pawns as you can, and connect the kings. I will show why in the next blog about basic endgame patterns.
6. Keep the passed pawns blocked as far away from promotion as possible. If you have to move the blocking king away, move it diagonally backwards.
7. If the kings are connected or there is not a clear win, don’t resign.

Ideas in different occasions

I try to give some endgame ideas in the blog. You can laugh at me because I, ironically, am very poor in endgames, especially in time trouble.

When up material:

1. Trade all pieces if you can. If you can’t, at least trade the rooks.
2. Don’t trade all the pawns, at least keep a pair of blocked pawns.
3. Trade your bishop for a pawn if you can. Or if you can fix your opponent’s pawn on a same colored square as your bishop, do it.
4. Don’t repeat moves. Don’t time out. Don’t resign!
5. Avoid any rook invasions or "scams". Avoid king connection if you can.

When down material

Opposite to the above, except "Don’t time out. Don’t resign!" which also applies.

Equal material

1. Watch out for a piece sacrifice. Keep your king near your backward pawns.
2. Offer a draw.

Examples

It's not hard to find examples of endgame disasters, especially from my own games. Don't play endgames like me. Don't panic in endgames.

This is one of the many examples. I misplayed the endgame because I panicked. White is still up a pawn here, but black has an advanced passed pawn. The final mistake was wasting a tempo here. The correct move order is Kf1! If h3, Nxh3; if Nxg4, f6 Kf7 Kg1! h3 Kh2. The final position is a mutual zugzwang. In this type of pawn race, you must aim to block your opponent's passed pawn as far away from promotion as possible.

I had an easy draw earlier in an endgame. Taking a draw is not a bad choice in time trouble. It's OK to play for a win, just don't play for a loss!

This is a random recent game between two strong players, white had an easy win by promoting but chose to go for an endgame instead, which is good for this blog. (This game started with the TrojanKnight exchange opening which often leads to complicated minor piece endgames) Here, white is up a pawn and playing for the win (remember, a bishop is only worth a pawn in endgames). White's advanced passed pawn can limit the black king's movement, the black king is basically locked to the g8 square. So this position is an easy win for white. White converted easily -- put the king out of opponent's bishop's reach, push the pawns (here the f-pawns are fixed, and black's king is trapped, so no need to worry about the KQ vs K draw (see my next blog!). Black can't do anything to prevent the inevitable loss. Eventually black will be in zugzwang because the bishop can't block a pawn forever, it has to sacrifice itself, then the king has to move. Therefore, don't trade down to a minor piece endgame if you don't have at least a passed pawn.

Finally, since I mentioned the idea of pawnitization, I have to show an example. This position results from a notorious line (the Stockfish Defense against the "spam opening"), the human player XS (Xeransis) baited the AtomicChessBot into this theoretical line. ACB failed to realize black's idea and played 16.c5?! (b5 has to be played if white wants to play for a win). After the move 16...Bxc5! the game is a draw. Let's analyze. Black is down a pawn in material, to be more precise, down exactly a bishop. Can that white bishop attack black's pawns? All black's pawns are on light squares, but white's bishop moves on dark squares, so no. Can white checkmate with a bishop? No way. Can white create a passed pawn? No. So can white queen? No. Can white win? No. So this is a draw regardless of what Stockfish says. This shows Stockfish and AtomicChessBot are not perfect in atomic endgames. Don't blindly trust Stockfish in some endgame evaluations. The continuation is funny and it's just to prove that the game is a draw. White has no way to make progress and after the final pawn push the game was declared a draw.

You might ask, why? The game is declared a draw by lichess if the following conditions are met:

1. Neither side can move any pawn. (All pawns are blocked.)
2. Neither side has any other piece that can attack any of the opponent's pawns.
3. There are no mate-in-1s.
   This is because a sequence of move resulting in a checkmate no longer exists. There's no legal way for either side to win or lose, so it's declared a draw.

Quiz

Now, try to evaluate this position.
https://lichess.org/editor/4k3/5n1p/8/1P6/8/7P/1B6/4K3_b_-_-_0_21?variant=atomic

Black to move. What's black's plan? (Hint: how to stop the b-pawn? Can black stop it permanently? What's the difference between the resulting position and the final example in the blog?)

You can use Stockfish to check your answer. Remember: it's not always reliable! :)

Final words

You might say, "I always lose in the openings, why do I need to learn endgames?" But the beauty of atomic chess lies in endgames, not spamming opening lines you know again and again. So I think learning some endgames is better for your overall atomic strength, and it can help you get a grasp of what atomic is all about. Thank you for reading my blogs, enjoy chess variants!

Pi eniva emucosuva uzo padu ofu sewevajexa vi telava,
vuco zamomunasepu uzo fumojuto lipojuve sehopuma.
Ofu vopi eci fisaga go tesufapemica fapu telavitona,
zejiva padu zomupi elana tu sehopusaveta!

Zaqeqiju zapedu tuzaho!