This article explains how the LobbyChess move evaluator works, the philosophy behind it, and a gallery of famous positions judged by the same standard now running on live games.
LobbyChess Move Evaluator
Why Ratings Don't Define Brilliance
The LobbyChess evaluator has expanded beyond the analyze game feature. It runs as you play, in the live commentary beside the board (featured in Stockfish mode only). Post game you can request a detailed evaluation. It's now incorporated into the Sunday Column, where every replayable board has an evaluation bar and a badge annotation on each move.
User rating does not change the evaluation.
A brilliant move is a truth about the position whether you are 800 or 2800.
Style and Accuracy
Dual Approach
Every move gets scored on two independent criteria. This allows a stylish move and an accurate move to each be measured on their own terms.
The grade
How much accuracy the move costs in the evaluation you gave up compared to the best alternative. This drives accuracy percentage.
The badge
The story layer. It lives in a separate field.
✗
Miss
You were handed a real chance because of an opponent's mistake. It could be a win, the only move that holds a draw, a forced mate, or something similar, and let it slip.
!
Great
The uniquely strong, non-obvious move. One right answer, and it was not obvious.
!!
Brilliant
The move creates a forced mate, or sacrifices real material soundly.
★
Legendary
The spectacle tier. A high piece parked where enemy pawns can legally take it.
Precedence when more than one could apply: Legendary, then Brilliant, then Great. A Miss is separate, and only ever lands on a move that was not best. Every badge also carries its reason in plain words, so a thrown away draw reads as "Blunder. Missed Draw." to offer further insight at a glance.
The Grading Ladder
Best Excellent Good ✓Inaccuracy ?!Mistake ?Blunder ??
Here are the principles.
The core idea of a Great Badge
Criticality and Difficulty
A Great means two things: there was exactly one right answer, and it was not obvious. The first half is easy to measure, there would exist a gap between the engine's best move and the second best. The second part we start from "there was only one move," then subtract the moves anyone would find anyway: recaptures, free grabs, saving a piece that was already attacked, the only legal reply, and some other factors.
Here is the position that makes the point. What would you call it?
Your call before you scroll:
Best
Bd7 · Black to move
The engine agrees this is the top move. Evaluation +0.63, 3.43 ahead of the runner-up. It cost 0.02 in accuracy.
Black is in check from Qc6, which also attacks the undefended a8 rook. The c8 bishop looks attacked too, but it is defended by the rook and the queen, so the rook is the only real worry. Bd7 handles it: the bishop blocks the check, attacks the queen, and clears c8 so the d8 queen also guards a8, and the rook is safe. Saving a loose rook is the first or second thing a player looks for, so Bd7 is obvious, Best, not a Great.
The bishop move is the only move that holds, so it is critical. But you find it naturally: you block the check with the first piece you look at, and you hit the queen while you do it and save the rook! Critical, yes. Difficult, no. So it gets graded Best. Now compare to another position where the only move that works is tricky:
! Great find.
Rcc6 · Black to move
The engine agrees this is the top move. Evaluation +1.34, 3.80 ahead of the runner-up. It cost 0.00 in accuracy.
Black is in check from Qb5. Two rooks can block on c6, but only the c8 rook works: the a6 rook is tied to defending the a4 knight, so Rac6 would drop it. Seeing that just one of two natural blocks holds is a real find, so it earns a Great.
! Great find.
Kf8 · Black to move
The engine agrees this is the top move. Evaluation -0.07, 1.75 ahead of the runner-up. It cost 0.00 in accuracy.
Nothing is in check and nothing looks like it is hanging, yet only one move keeps Black level. Every natural bishop retreat costs a pawn; the quiet king step to f8 is the single move that holds. A do-nothing king move is easy to overlook, so it is a Great.
What makes the LobbyChess algorithm different
We only grade chess truth
Some grading systems tune the badge to your rating, so the same move earns a medal for a beginner and nothing for a master, because the badge is really guessing "impressive for a player of your level." That is a reasonable thing to measure. It is just a different philosophy.
Our badge depends only on the board and the move. The brilliancy you found at 900 is still a brilliancy when you are 2500. Take a look at this example:
! Great find.
It was the only move that held the position, so a system that rewards the only good move calls it a Great.
Best
Black is in check from Qc6, which also attacks the undefended a8 rook. The c8 bishop looks attacked too, but it is defended by the rook and the queen, so the rook is the only real worry. Bd7 handles it: the bishop blocks the check, attacks the queen, and clears c8 so the d8 queen also guards a8, and the rook is safe. Saving a loose rook is the first or second thing a player looks for, so Bd7 is obvious, Best, not a Great.
There is a consistency payoff, too. A game with a run of strong play, a rating-scaled grader might hand out five brilliant medals. We hand out four. It must meet criteria for addition: is it a forced mate, a real sacrifice, a genuine, non-obvious move.
See For Yourself
3 Tiers of Amazing Moves
These are the badges worth celebrating, and they come in three rising levels. A Great is the uniquely strong, non-obvious move. A Brilliant creates a forced mate or soundly sacrifices real material. A Legendary, the rarest of the three, is a valuable piece parked defiantly where enemy pawns can take it. Press Play on any board to see the move that earns each one.
! Great find.
Kf8 · Black to move
The engine agrees this is the top move. Evaluation -0.07, 1.75 ahead of the runner-up. It cost 0.00 in accuracy.
Nothing is in check and nothing looks like it is hanging, yet only one move keeps Black level. Every natural bishop retreat costs a pawn; the quiet king step to f8 is the single move that holds. A do-nothing king move is easy to overlook, so it is a Great.
!! Brilliant.
Qb8+ · White to move
The engine agrees this is the top move. Evaluation forces mate in 2, the line forces mate. It cost 0.00 in accuracy.
Morphy's Opera Game, Paris 1858. 16.Qb8+ throws the queen in front of the rook; after ...Nxb8, 17.Rd8 is mate. A queen sacrifice that forces mate is a Brilliant.
★ Legendary.
Qg3 · Black to move
The engine agrees this is the top move. Evaluation +5.16, 0.39 ahead of the runner-up. It cost 0.00 in accuracy.
Marshall vs Levitsky, 1912, the famous 'shower of gold coins.' The queen steps to g3 where both the f2 and h2 pawns attack it, refuses to be taken (capturing loses), and is still the best move on the board. A great piece planted defiantly in pawn fire is the Legendary tier.
The Special Miss Badge
Miss is the one badge that is not praise. It is the only badge a less-than-best move can earn, and it marks a real chance let slip: a win, the only drawing move, or a forced mate. It always names what was missed, shown as a two-layer verdict like "Blunder. Missed Draw." Press Play to see one.
Blunder✗ Missed Draw
Kg8 · White to move
The engine's own top pick was Kg7, not the move played. Evaluation +0.00, 5.25 ahead of the runner-up. It cost 5.00 in accuracy.
The mirror of the Reti Great, one square off. 1.Kg8 walks away from both pawns instead of toward them, throwing away the only drawing move (Kg7), so the game is lost. It reads in two layers: Blunder for the result, Missed Draw for the exact chance let slip. Same board as the Reti Kg7 Great, opposite verdict.
The gallery
Great moments, graded
Every position below runs through the grader, so the verdict you see is the verdict a live game would show. The moves that correctly earn nothing can be just as telling.
Great: the genuine finds
The engine's clear best, not obvious, with a real gap to the second choice. This includes the only move that holds a draw when everything else loses. This is what a Great is meant to reward.
! Great find.
Rcc6 · Black to move
The engine agrees this is the top move. Evaluation +1.34, 3.80 ahead of the runner-up. It cost 0.00 in accuracy.
Black is in check from Qb5. Two rooks can block on c6, but only the c8 rook works: the a6 rook is tied to defending the a4 knight, so Rac6 would drop it. Seeing that just one of two natural blocks holds is a real find, so it earns a Great.
! Great find.
Kf8 · Black to move
The engine agrees this is the top move. Evaluation -0.07, 1.75 ahead of the runner-up. It cost 0.00 in accuracy.
Nothing is in check and nothing looks like it is hanging, yet only one move keeps Black level. Every natural bishop retreat costs a pawn; the quiet king step to f8 is the single move that holds. A do-nothing king move is easy to overlook, so it is a Great.
! Great find.
Qe1 · Black to move
The engine agrees this is the top move. Evaluation +7.52, 8.53 ahead of the runner-up. It cost 0.00 in accuracy.
Black is winning by a lot, but only one move preserves it: the quiet Qe1. Out of twenty-four legal moves it is the single one that holds the advantage, everything else lets it slip. One precise, non-obvious move with a huge gap to the rest is the definition of a Great.
! Great find.
Be6 · Black to move
The engine agrees this is the top move. Evaluation +2.43, 3.33 ahead of the runner-up. It cost 0.31 in accuracy.
Byrne-Fischer, New York 1956, the Game of the Century. The thirteen-year-old Fischer plays 17...Be6, ignoring the attack on his queen and offering it for a crushing initiative. Our grader rates it a Great, a uniquely strong move, rather than a Brilliant: the sacrifice detector reads the piece that moved, the bishop, not the queen waiting behind it, so the deeper point slips past. An honest edge.
! Great find.
Kg7 · White to move
The engine agrees this is the top move. Evaluation +0.00, 5.19 ahead of the runner-up. It cost 0.00 in accuracy.
Reti's 1921 study, the famous lesson in the king's hidden speed. 1.Kg7 heads toward the c-pawn and the black h-pawn at once and is the only move that saves an ending that looks dead lost, holding the draw while every other move loses. The single move that rescues a lost position is a Great.
! Great find.
Bb3 · White to move
The engine agrees this is the top move. Evaluation -0.02, 5.64 ahead of the runner-up. It cost 0.00 in accuracy.
A blocked ending that looks like anything should hold, but it does not: only Bb3 keeps the balance, and every other move loses by about six pawns. The one saving move in a position that looks dead drawn is a Great.
Great, withheld: critical but obvious
Each of these is objectively fine or even best, but a human would find it without effort, so it earns no badge. These are the false medals we deliberately rule out.
Best
Bd7 · Black to move
The engine agrees this is the top move. Evaluation +0.63, 3.43 ahead of the runner-up. It cost 0.02 in accuracy.
Black is in check from Qc6, which also attacks the undefended a8 rook. The c8 bishop looks attacked too, but it is defended by the rook and the queen, so the rook is the only real worry. Bd7 handles it: the bishop blocks the check, attacks the queen, and clears c8 so the d8 queen also guards a8, and the rook is safe. Saving a loose rook is the first or second thing a player looks for, so Bd7 is obvious, Best, not a Great.
Blunder ??
Rac6 · Black to move
The engine's own top pick was Rcc6, not the move played. Evaluation +1.18, 3.53 ahead of the runner-up. It cost 3.69 in accuracy.
The tempting block that fails. Rac6 interposes with the a6 rook, but that rook was the only thing defending the a4 knight, so White simply wins the knight. It loses material, so it is a blunder and earns nothing.
Your call before you scroll:
Best
Bxa4 · Black to move
The engine agrees this is the top move. Evaluation +1.93, 0.98 ahead of the runner-up. It cost 0.00 in accuracy.
Bxa4 just wins a free pawn: nothing defends a4, so there is no recapture. It is the best move and it wins material, but grabbing a free pawn is the first thing anyone sees, so it is obvious, not a Great.
Best
Be7 · Black to move
The engine agrees this is the top move. Evaluation -0.26, 4.73 ahead of the runner-up. It cost 0.07 in accuracy.
Black is in check from the rook on e5 with only two legal replies, and the king has no square. The alternative hangs the queen, so Be7 is essentially forced. A move you play because nothing else is legal is not a find, so there is no badge, even though it is clearly best.
Excellent
Nxe5 · Black to move
The engine's own top pick was Nf5, not the move played. Evaluation -1.17, 0.25 ahead of the runner-up. It cost 0.12 in accuracy.
Nxe5 takes a knight and is simply recaptured by the rook, an even trade rather than a sacrifice. Because no real material is given up, no Brilliant fires, and it is not the engine's top move anyway.
Brilliant: sound sacrifices and forced mates
A sound sacrifice, or a move that creates a forced mate. Some of the most famous sacrifices ever played live here. The last card walks an existing mate forward, which is strong but not a new brilliancy.
!! Brilliant.
Qh4 · Black to move
The engine agrees this is the top move. Evaluation +7.97, 5.12 ahead of the runner-up. It cost 0.00 in accuracy.
Qh4 conjures a forced mate that did not exist one move earlier. The move that brings a forced mate into being is exactly what a Brilliant rewards.
Your call before you scroll:
!! Brilliant.
Qb8+ · White to move
The engine agrees this is the top move. Evaluation forces mate in 2, the line forces mate. It cost 0.00 in accuracy.
Morphy's Opera Game, Paris 1858. 16.Qb8+ throws the queen in front of the rook; after ...Nxb8, 17.Rd8 is mate. A queen sacrifice that forces mate is a Brilliant.
!! Brilliant.
Qg8+ · White to move
The engine agrees this is the top move. Evaluation forces mate in 2, the line forces mate. It cost 0.00 in accuracy.
The textbook smothered mate: 1.Qg8+ Rxg8 2.Nf7 mate. The queen is sacrificed to force the king's own rook to seal its last escape square. A Brilliant.
!! Brilliant.
Qxh7+ · White to move
The engine agrees this is the top move. Evaluation forces mate in 10, the line forces mate. It cost 0.00 in accuracy.
Edward Lasker vs George Thomas, London 1912. 11.Qxh7+ Kxh7 drags the king into the open for a march that ends in mate. The queen sacrifice is a Brilliant.
!! Brilliant.
Bxh7+ · White to move
The engine agrees this is the top move. Evaluation +4.40, 4.27 ahead of the runner-up. It cost 0.00 in accuracy.
Emanuel Lasker vs Johann Bauer, Amsterdam 1889, the original double bishop sacrifice. 15.Bxh7+ rips open the king, with Bxg7 to follow. Giving up the first bishop is a Brilliant.
!! Brilliant.
Rxc3 · Black to move
The engine agrees this is the top move. Evaluation +6.31, 2.98 ahead of the runner-up. It cost 0.00 in accuracy.
Rotlewi-Rubinstein, Lodz 1907, 'Rubinstein's Immortal.' 22...Rxc3 tears away the knight and overloads White's queen, launching the storm of rook and queen sacrifices to come. A Brilliant.
!! Brilliant.
Ba3 · White to move
The engine agrees this is the top move. Evaluation +4.70, 1.21 ahead of the runner-up. It cost 0.00 in accuracy.
Botvinnik-Capablanca, AVRO 1938. 30.Ba3 offers the bishop to pull Black's queen off the passed e-pawn and clear the way for Nh5+. A deflection sacrifice, and a Brilliant.
!! Brilliant.
Qxf6 · White to move
The engine's own top pick was Qg4, not the move played. Evaluation +0.31, 0.04 ahead of the runner-up. It cost 0.18 in accuracy.
Nezhmetdinov-Chernikov, Rostov 1962. 12.Qxf6 gives the queen for two pieces and a lasting attack rather than a forced mate, the classic compensation sacrifice. The engine's own first choice is Qg4, but Qxf6 is sound enough that the sacrifice still reads Brilliant.
!! Brilliant.
Bh3 · Black to move
The engine's own top pick was Be4, not the move played. Evaluation +1.65, 0.74 ahead of the runner-up. It cost 0.00 in accuracy.
Topalov-Shirov, Linares 1998. 47...Bh3 throws the bishop under the pawns so Black's connected passed pawns can break through, a stunning endgame sacrifice that reads Brilliant.
!! Brilliant.
Rxd4 · White to move
The engine agrees this is the top move. Evaluation -0.41, 0.47 ahead of the runner-up. It cost 0.00 in accuracy.
Kasparov-Topalov, Wijk aan Zee 1999. 24.Rxd4 opens the immortal king hunt with a rook sacrifice. The payoff is many moves away, so the eval here is only level, but the grader still sees the material given up: Brilliant.
! Great find.
Nf6 · White to move
The engine agrees this is the top move. Evaluation forces mate in 4, the line forces mate. It cost 0.00 in accuracy.
The mate was already forced before this move, so Nf6 only walks it forward rather than creating anything new. That keeps it a Great, a unique forcing move, rather than a Brilliant, which is saved for the move that starts the mate.
Legendary: a piece that steps into the fire
The rarest tier. A bishop or higher parks where enemy pawns can legally take it, uncaptured, as the best move on the board. It fires for either color.
★ Legendary.
Qg3 · Black to move
The engine agrees this is the top move. Evaluation +5.16, 0.39 ahead of the runner-up. It cost 0.00 in accuracy.
Marshall vs Levitsky, 1912, the famous 'shower of gold coins.' The queen steps to g3 where both the f2 and h2 pawns attack it, refuses to be taken (capturing loses), and is still the best move on the board. A great piece planted defiantly in pawn fire is the Legendary tier.
★ Legendary.
Qg6 · White to move
The engine agrees this is the top move. Evaluation +5.10, 0.48 ahead of the runner-up. It cost 0.03 in accuracy.
Pawn defiance from White's side: Qg6 lands where both the f7 and h7 pawns attack it, offers no capture of its own, and is still the best move. The color mirror of Marshall's Qg3, and just as Legendary.
The two-layer Miss
A Miss keeps the objective grade and names the chance overlooked, so a thrown draw reads 'Blunder, Missed Draw', never a bare mark. Two of these reuse a Great or Brilliant board with the wrong move. The last is a control: a forced mate merely made slower is not a Miss.
Blunder✗ Missed Draw
Kg8 · White to move
The engine's own top pick was Kg7, not the move played. Evaluation +0.00, 5.25 ahead of the runner-up. It cost 5.00 in accuracy.
The mirror of the Reti Great, one square off. 1.Kg8 walks away from both pawns instead of toward them, throwing away the only drawing move (Kg7), so the game is lost. It reads in two layers: Blunder for the result, Missed Draw for the exact chance let slip. Same board as the Reti Kg7 Great, opposite verdict.
Blunder✗ Missed Mate
Qxe6+ · White to move
The engine's own top pick was Qb8+, not the move played. Evaluation forces mate in 2, the line forces mate. It cost 5.00 in accuracy.
The Morphy position again, with the wrong move. Instead of the forced mate 16.Qb8+, White grabs the queen with 16.Qxe6+. It wins material but throws the mate away, so it is a Blunder and a Missed Mate. Same board as the Qb8+ Brilliant, opposite verdict.
Mistake✗ Missed Opportunity
a3 · White to move
Teaching fixture with hand-set evaluations (validated in the classifier's unit tests).
The third kind of Miss. The opponent's previous move handed back about a pawn, and a passive reply like 1.a3 lets that edge slip back to equal. That is a Mistake for the result and a Missed Opportunity for the chance not taken.
Excellent
Nf7+ · White to move
The engine's own top pick was Qg8+, not the move played. Evaluation forces mate in 2, the line forces mate. It cost 0.01 in accuracy.
A control for the Miss rule. The quickest mate is 1.Qg8+ (mate in two); 1.Nf7+ instead keeps a forced mate, just a slower one. Because the win is delayed, not lost, it is not a Miss. It grades Excellent, with no badge.
Correct restraint: no badge, and that is right
A strong move that is genuinely not a unique find, so staying quiet is the right call. Kasparov's octopus knight is best by a whisker over the runner-up: unforgettable, but not uniquely hard by the numbers.
Best
Nd3 · Black to move
The engine agrees this is the top move. Evaluation +0.47, 0.04 ahead of the runner-up. It cost 0.06 in accuracy.
Karpov-Kasparov, 1985 World Championship, Game 16. 16...Nd3 plants the famous 'octopus' knight that paralyzes White's pieces. It is a lasting positional bind rather than a tactic, and it is best by only a hair over the next move, so there is no unique-move badge to give. Unforgettable, and correctly no badge.
Motifs we do not badge yet
Strong strategic and endgame ideas the classifier does not recognize as a category yet: zugzwang, restriction, underpromotion. Each maps to a planned detector on the roadmap.
Best
h6 · Black to move
The engine agrees this is the top move. Evaluation +4.65, 0.30 ahead of the runner-up. It cost 0.10 in accuracy.
Saemisch-Nimzowitsch, Copenhagen 1923, the Immortal Zugzwang Game. 25...h6 is the quiet little move that completes the bind and leaves White in zugzwang. Black is already winning, so a calm consolidating move earns no badge, which is the correct restraint.
Best
Ba7 · White to move
The engine agrees this is the top move. Evaluation +0.90, 0.38 ahead of the runner-up. It cost 0.06 in accuracy.
Karpov-Unzicker, Nice 1974. 24.Ba7 tucks the bishop out of reach and smothers Black's queenside for good. Pure strategy, not a tactic, so no badge, exactly the restraint we want.
Best
c8=R · White to move
The engine agrees this is the top move. Evaluation forces mate in 17, the line forces mate. It cost 0.00 in accuracy.
The Saavedra study. 1.c8=R is the only winning move, since promoting to a queen allows 1...Rc4+ and stalemate. It is best and it mates, but the grader has no badge for underpromotion yet and does not decorate routine winning moves, so it shows nothing. A gap we know about.
Honest gaps and fragile calls
The edges of the system: real brilliancies the grader misses today (a deep king march, a windmill), and verdicts that lean on the exact engine reading.
Inaccuracy ?!
Kh2 · White to move
The engine's own top pick was c3, not the move played. Evaluation +4.15, 0.15 ahead of the runner-up. It cost 0.42 in accuracy.
Short-Timman, Tilburg 1991. 31.Kh2 begins the celebrated king march, Kh2-g3-f4-g5 straight into a mating net. The payoff is far over the horizon, so the engine prefers a concrete move and Kh2 does not even read as best. The idea is beyond a move-by-move grader's reach.
Best
Bf6 · White to move
The engine agrees this is the top move. Evaluation +4.72, 4.72 ahead of the runner-up. It cost 0.00 in accuracy.
Torre-Lasker, Moscow 1925. 25.Bf6 sets up the classic windmill, winning through a chain of discovered checks. The grader does not recognize the windmill pattern, and since the bishop was itself under attack the move even looks like a routine retreat, so nothing fires. A known blind spot.
! Great find.
fxg5 · White to move
The engine agrees this is the top move. Evaluation +2.98, 2.96 ahead of the runner-up. It cost 0.00 in accuracy.
White is walking into a forced mate (Black's ...g4+ breaks through). fxg5 removes the g5 pawn that makes it work, snuffing out the mate and staying a pawn up. Everything that earns a Brilliant here is about attack, so this purely defensive save lands as a Great, a category we would still like to add.
! Great find.
Kf1 · White to move
Teaching fixture with hand-set evaluations (validated in the classifier's unit tests).
The king is in check and must move, and Kf1 is the one square that keeps the position. Choosing the single safe king square is a genuine find, so it grades a Great. This one is a teaching example: at full depth the engine actually prefers Kf3, so it illustrates the rule rather than standing as a live verdict.
Negative controls: correctly no badge
Famous blunders and traps. The point is what does not happen: a losing move never earns a badge, no matter how wild it looks.
Blunder ??
Qe3 · Black to move
The engine's own top pick was Kg8, not the move played. Evaluation +0.00, 0.58 ahead of the runner-up. It cost 5.00 in accuracy.
Deep Fritz-Kramnik, Bonn 2006. 34...Qe3 allows 35.Qh7 mate in one, the most famous one-move blunder in World Championship history. It grades a blunder with no badge: nothing flashy is ever awarded to a losing move.
Blunder ??
Ng5 · White to move
The engine's own top pick was Qc7, not the move played. Evaluation +3.77, 0.20 ahead of the runner-up. It cost 5.00 in accuracy.
Petrosian-Bronstein, Amsterdam 1956. 36.Ng5 simply leaves the queen on d6 hanging to the f5 knight. Total board control does not excuse it, a blunder, no badge.
Good ✓
Bxh2 · Black to move
The engine's own top pick was a6, not the move played. Evaluation -0.04, 0.08 ahead of the runner-up. It cost 0.37 in accuracy.
Spassky-Fischer, Reykjavik 1972, Game 1: the famous 29...Bxh2, long marked a blunder for walking into g3 and trapping the bishop. The grader gives no badge, it is a pawn grab, not a sacrifice. The twist: modern engines do not even confirm the blunder, rating it barely off best.
The whole game
A game is a story, not forty snapshots
Everything above grades a single position. But a mating attack is one idea, not five, and we do not award five badges stapled to one combination. After a game finishes, a second pass reads the whole thing and keeps a single anchor badge per forced mate, the move that commits to the attack, and quietly demotes the routine follow-ups. Step through these and watch the live badges collapse to one on review.
Morphy's Opera Game: one Brilliant, not three badges
Starting position
#
Move
Live badge
Reviewed
1
Qb8+
Brilliant !!
Brilliant !!
2
Nxb8
-
-
3
Rd8#
Great !
-
The queen sacrifice 16.Qb8+ creates the mate and keeps the Brilliant. A single-position view also flags the forced finish 17.Rd8# as a Great (it is the only move), so review would show two badges on one three-move attack. Stage 2 keeps the anchor and demotes the routine mate to its plain grade.
Smothered mate: the queen sacrifice anchors the episode
Starting position
#
Move
Live badge
Reviewed
1
Qg8+
Brilliant !!
Brilliant !!
2
Rxg8
-
-
3
Nf7#
Great !
-
The textbook 1.Qg8+ hands the queen to the rook so the knight can deliver Nf7#. The sacrifice is the Brilliant anchor; the forced knight mate, a provisional Great on its own, is demoted.
A routine mate in 3: one anchor on the initiating check
Starting position
#
Move
Live badge
Reviewed
1
Bxd6
-
-
2
Qe3+
Great !
Great !
3
Bc5
-
-
4
Qxc5+
Great !
-
5
Kb7
-
-
6
Qb6#
Great !
-
No sacrifice here, just a forced mate where every White check reads as a unique 'only move' Great on its own. Stage 2 keeps ONE, and the anchor is the FIRST forcing move (Qe3+), the move that commits to the mating attack, not the check closest to delivery. The mate-distance tiebreak that once pulled the badge to the end of the run was the bug the mate corpus caught.
The guardrails
What keeps a badge worth something
Three rules behind every badge
Precision check second pass. We would rather Legendary fire rarely and accurately.
No medals while you are losing badly. A stylish move that leaves you lost keeps its plain grade and earns no badge. The prestige floor prevents this.
No badges in dead drawn positions. Shuffling in a drawn fortress is not a string of great saves either.
A dead-drawn fortress in LobbyChess only collects a Great under special circumstances: when one move holds the draw and every other move loses.
Deeper Game Review
Coming Soon
Some of the deepest hidden brilliancies still slip past in the moment. The most famous example on this page, the queen brashly stepping into a wall of pawns, is so deep in calculation that it sits ninth on the engine's list until you search very deep, so at live speed it does not yet read as near best. It also shows deep human calculation can still be stronger than a 3200+ ELO machine.
Soon we'll be allowing the grader to show more of its work: the concrete refutation behind a Miss, the full exchange behind a sacrifice, and an Explain button that walks you through why. Until then, enjoy the new Lobbychess Review Game.