Prepare against Klaus Mertens
DEU · World #22,938 classical · FIDE ID 4618815
When preparing against Klaus Mertens, expect 1.Nf3 in 75% of White games. Against 1.e4 the reply is 1...c5 (66% of games); against 1.d4, 1...Nf6 (100%). Lowest win rate among frequent openings: English Opening: Reverse Sicilian as Black, 6.7% over 15 games.
Our database contains 397 games by Klaus Mertens, covering Apr 2003 to Sep 2026. Below you'll find Klaus Mertens's most-played openings with White and Black, career performance record, notable wins and top events — everything you need to scout Klaus Mertens before a game. You can open the same data in the free interactive preparation workstation, which builds a move-by-move opening tree from every game.
Ratings
| Time control | Current | Peak | Peak date |
|---|---|---|---|
| Classical | 2,034 | 2,163 | Oct 2003 |
| Rapid | 2,039 | 2,058 | May 2015 |
Performance record
| Split | Games | Wins | Draws | Losses | Win rate |
|---|---|---|---|---|---|
| Overall | 397 | 119 | 171 | 107 | 30.0% |
| As White | 191 | 69 | 86 | 36 | 36.1% |
| As Black | 206 | 50 | 85 | 71 | 24.3% |
Move-by-move preparation stats
Straight from the preparation tree built over all of Klaus Mertens's games — the same tree the interactive prep board lets you walk to any depth. Scores are from Klaus Mertens's side.
First moves as White (191 games)
| Move | Games | Share | Player score |
|---|---|---|---|
| Nf3 | 143 | 74.9% | 58.4% |
| d4 | 44 | 23.0% | 60.2% |
| e4 | 2 | 1.0% | 25.0% |
| c4 | 1 | 0.5% | 50.0% |
| b3 | 1 | 0.5% | 100.0% |
Main lines as White
- 1.Nf3 — 75% of White games, 58.4% score
- …Nf6 (43% of these games) — Mertens usually continues g3 (61.5% score)
- …d5 (24% of these games) — Mertens usually continues g3 (50.0% score)
- …c5 (12% of these games) — Mertens usually continues g3 (61.1% score)
- 1.d4 — 23% of White games, 60.2% score
- …Nf6 (55% of these games) — Mertens usually continues c4 (60.5% score)
- …d5 (23% of these games) — Mertens usually continues c4 (55.6% score)
- …f5 (7% of these games) — Mertens usually continues g3 (50.0% score)
As Black against 1.e4 (91 games)
| Move | Games | Share | Player score |
|---|---|---|---|
| c5 | 60 | 65.9% | 48.3% |
| c6 | 14 | 15.4% | 35.7% |
| d5 | 9 | 9.9% | 50.0% |
| d6 | 7 | 7.7% | 50.0% |
| g6 | 1 | 1.1% | 0.0% |
As Black against 1.d4 (69 games)
| Move | Games | Share | Player score |
|---|---|---|---|
| Nf6 | 69 | 100.0% | 42.8% |
Klaus Mertens's chess games
All 397 games by Klaus Mertens in the Chess.ceo database (Apr 2003 - Sep 2026) are free to browse, search and replay: filter by opening, opponent, event or date on the player page, or step through any game on the analysis board. Record: 119 wins, 171 draws, 107 losses.
Openings as White
| ECO | Opening | Games | W/D/L | Win rate |
|---|---|---|---|---|
| D02 | Réti Opening | 58 | 28/19/11 | 48.3% |
| E63 | Réti Opening: Symmetrical Defense | 21 | 6/9/6 | 28.6% |
| A30 | English Opening | 14 | 7/7/0 | 50.0% |
| A47 | Indian Defense | 14 | 4/8/2 | 28.6% |
| D02 | Queen's Pawn Game | 12 | 4/6/2 | 33.3% |
| A81 | Dutch Defense | 11 | 3/7/1 | 27.3% |
| A49 | Modern Defense | 9 | 1/7/1 | 11.1% |
| A37 | English Opening: Symmetrical | 6 | 1/3/2 | 16.7% |
| E67 | King's Indian Defense: Fianchetto Variation | 5 | 1/3/1 | 20.0% |
| E19 | Queen's Indian Defense | 4 | 3/1/0 | 75.0% |
Openings as Black
| ECO | Opening | Games | W/D/L | Win rate |
|---|---|---|---|---|
| B43 | Sicilian | 46 | 15/18/13 | 32.6% |
| A47 | Indian Defense | 16 | 6/6/4 | 37.5% |
| A25 | English Opening: Reverse Sicilian | 15 | 1/7/7 | 6.7% |
| E12 | Queen's Indian Defense | 13 | 3/5/5 | 23.1% |
| A30 | English Opening | 11 | 2/8/1 | 18.2% |
| B23 | Sicilian: Closed | 10 | 2/4/4 | 20.0% |
| B01 | Scandinavian Defense: Main Line | 8 | 3/2/3 | 37.5% |
| E11 | Catalan | 7 | 0/3/4 | 0.0% |
| B07 | Pirc Defense | 7 | 1/5/1 | 14.3% |
| E43 | Nimzo-Indian: Rubinstein System | 5 | 2/1/2 | 40.0% |
Notable wins
| Date | Opponent | Elo | Event | ECO |
|---|---|---|---|---|
| Jan 1993 | Roland Fritz | 2,320 | 04th Seefeld Open | D30 |
| Jul 1990 | Bodin Marjanovic | 2,295 | 05th Wattens Open | A04 |
| Jul 2013 | Norbert Heck | 2,282 | 16th Karl Mala Memorial Open A | A30 |
| Jan 1996 | Guenther Ballon | 2,270 | 7th Seefeld Open | D13 |
| Aug 2014 | Leonid Sobolevsky | 2,239 | 17th Karl Mala Memorial Open A | B46 |
Top events
| Event | Year | Games | Score | TPR |
|---|---|---|---|---|
| ch-Hessen MVT | 1995 | 11 | 4.5 | 2,008 |
| 23. Rheinland-Pfalz Senioren Open | 2026 | 9 | 5 | 1,944 |
| 12th Seefeld Open | 2001 | 9 | 4.5 | 1,961 |
| 20th Rheinland Pfalz Seniors Open | 2023 | 9 | 6 | 2,185 |
| 25th Liechtenstein Open | 2007 | 9 | 4 | 2,101 |
| 13th Seefeld Open | 2002 | 9 | 5 | 2,116 |
| 10th Seefeld Open | 1999 | 9 | 4.5 | 2,117 |
| 04th Seefeld Open | 1993 | 9 | 4.5 | 2,039 |
Interactive opening tree from all 397 games, weak-spot detection and engine analysis.
Start preparationFrequently asked questions
Where can I find Klaus Mertens's chess games?
397 games by Klaus Mertens, from Apr 2003 to Sep 2026, are free to browse and replay move by move — no signup needed. The preparation view groups them into an opening tree showing every line Klaus Mertens has played.
What does Klaus Mertens play on the first move as White?
Across 191 games with White in our database, Klaus Mertens opens with 1.Nf3 (75% of games), 1.d4 (23% of games), 1.e4 (1% of games). Against 1.e4 as Black, Klaus Mertens answers 1...c5 (66% of games), 1...c6 (15% of games), 1...d5 (10% of games). Against 1.d4: 1...Nf6 (100% of games).
What openings does Klaus Mertens play as White?
As White, Klaus Mertens's most-played openings in our database are: Réti Opening (58 games, 48.3% win rate); Réti Opening: Symmetrical Defense (21 games, 28.6% win rate); English Opening (14 games, 50.0% win rate). The full breakdown of 191 games with White is in the table above.
What openings does Klaus Mertens play as Black?
As Black, Klaus Mertens most often plays: Sicilian (46 games, 32.6% win rate); Indian Defense (16 games, 37.5% win rate); English Opening: Reverse Sicilian (15 games, 6.7% win rate). See the table above for the top ten Black openings across 206 games.
What is Klaus Mertens's FIDE rating?
Klaus Mertens is currently rated 2,034 in classical chess, 2,039 in rapid. Peak classical rating: 2,163 (Oct 2003).
How many games has Klaus Mertens played?
Our database contains 397 games by Klaus Mertens, covering Apr 2003 to Sep 2026. Overall record: 119 wins, 171 draws, 107 losses (30.0% win rate).
How do I prepare against Klaus Mertens?
397 games by Klaus Mertens reveal their opening repertoire, most-played lines, and the variations where they score worst — the raw material for targeted preparation. The interactive opening tree lets you walk every line to any depth.