Your #1 Rating Leak
King Safety
Why this keeps happening
Your move allowed a forced checkmate that a different move would have stopped.
Deterministic analysis (Stockfish + fixed heuristics). No invented insights.
More games may change results as stronger patterns emerge.
Your most damaging patterns
Grouped by weakness category, ranked by frequency, evaluation cost, and recurrence
1
King Safety
Weaknesses around your king that let the opponent launch or sustain attacks.
47% of your total damage
3 specific patterns
Mate Threat Missed (D)
Your move allowed a forced checkmate that a different move would have stopped.
Severity 5/8
6 occurrences
5 games
avg -91.9 pawns/error
46% of your total damage
King Safety - Shelter Weakened (D)
You allowed pawn advances near your king that shattered your defensive shelter.
Severity 3/8
8 occurrences
8 games
avg -0.8 pawns/error
1% of your total damage
Back-Rank Weakness
Your king had no escape square (no luft), enabling decisive back-rank threats.
Severity 2/8
2 occurrences
2 games
avg -1.7 pawns/error
0% of your total damage
2
Material Loss
Patterns that cost you pieces or allow the opponent to win material.
27% of your total damage
3 specific patterns
Fork Exposed (D)
Your pieces were left on squares where the opponent could fork two at once, winning material.
Severity 6/8
25 occurrences
21 games
avg -6.0 pawns/error
13% of your total damage
Pin Exposed (D)
Your piece was pinned against a more valuable piece behind it, restricting your options and costing material.
Severity 6/8
18 occurrences
15 games
avg -7.6 pawns/error
12% of your total damage
Skewer Exposed (D)
Your high-value piece was attacked and forced to move, leaving the piece behind it to be captured.
Severity 4/8
14 occurrences
9 games
avg -2.3 pawns/error
3% of your total damage
3
Endgame
Failures in technique, king activity, or pawn management in the endgame.
26% of your total damage
3 specific patterns
Passed Pawn - Rook Behind Miss (O)
You failed to place your rook behind your passed pawn, reducing its pushing power.
Severity 4/8
60 occurrences
28 games
avg -3.0 pawns/error
15% of your total damage
Passed Pawn - Push Failure (O)
You had a passed pawn but failed to advance it at the right moment.
Severity 5/8
13 occurrences
9 games
avg -8.3 pawns/error
9% of your total damage
Passed Pawn - Blockade Failure (D)
You let the opponent advance a passed pawn by failing to blockade it in time.
Severity 3/8
12 occurrences
7 games
avg -1.6 pawns/error
2% of your total damage
Keep or share this report
Link: https://blackboxchess.app/report/bc690916-3d6e-46dc-bdeb-9c9f80313059
Get daily drills from your own games
Create a free account and we'll email you a drill every day pulled from positions where you went wrong. Your games. Your mistakes. Fixed.
Report ID: bc690916-3d6e-46dc-bdeb-9c9f80313059
Where your mistakes happen
Breakdown of errors by game phase across your analyzed games.
Your weakest phase is middlegame - drill it below.
Where things first went wrong
Game 1, move 9 (Black): b6
One number to watch
You converted your advantage in 78% of games where you achieved a significant advantage.
(above average)
Examples from your games
| # |
Opponent |
Date |
Result |
Blunders |
Inaccuracies |
| 4 |
Jamaicanknights |
2026.09.01 |
0-1 |
1 |
0 |
| 11 |
Ugly1-2 |
2026.09.02 |
1-0 |
2 |
2 |
| 3 |
Abhinav_aggarwal |
2026.09.01 |
0-1 |
0 |
1 |
What leaving the book costs you
Every opening has a book: the established moves that strong players have settled on.
In 21 of your 66 games in the openings below, your first move outside the book made your position worse by a pawn or more.
French Defense as Black
10 of 37 games, 1.7 pawns each time
Costliest: Bf5 on move 17, which cost 3.6 pawns.
Nimzo-Indian Defense as Black
4 of 6 games, 1.9 pawns each time
Costliest: Nb1+ on move 7, which cost 3.5 pawns.
Queen's Gambit Declined as White
3 of 9 games, 1.7 pawns each time
Costliest: Qa4+ on move 5, which cost 2.0 pawns.
Queen's Pawn Game as White
1 of 7 games, 3.9 pawns each time
Costliest: e4 on move 5, which cost 3.9 pawns.
Slav Defense as White
3 of 7 games, 1.2 pawns each time
Costliest: e4 on move 9, which cost 1.3 pawns.
A pawn here is the engine's unit of advantage: 1.0 is about the value of one pawn. The bar is the total across your games in that opening.
Games where your first move outside the book cost less than a pawn are not counted, and openings you played fewer than 3 times are not listed. How this is measured
A personalized opening video takes one of these from your own game: the move you played, the move the engine recommends, and why.
See your opening videos →
See where you leave book: personalized opening videos
For each opening where you consistently stray from theory, we build a short narrated video from your own games: what you played, what the engine recommends, and why it matters. Generated and emailed to you, usually within an hour.
Starting at $5 per video, less as you add more. Already have one delivered? Share it on Instagram, TikTok, YouTube, or Facebook, tag ChessJitsu, and earn your next one free.
Get personalized opening videos →
Unlocked
This report is unlocked. You can download the PDF.
Make it go away for good: $12/mo
This report is a snapshot. The subscription is the fix that keeps working: every new game you play is re-analyzed each week, and the positions you got wrong resurface on a spaced-repetition schedule until the pattern goes away.
You also get the endgame trainer and a free personalized opening video credit every week. Cancel any time.
See the subscription →
