Prepare against Jan Willem Koelmans
NLD · World #80,738 classical · FIDE ID 1011588
When preparing against Jan Willem Koelmans, expect 1.d4 in 95% of White games. Against 1.e4 the reply is 1...c5 (100% of games); against 1.d4, 1...d5 (89%).
Our database contains 85 games by Jan Willem Koelmans, covering Oct 2003 to Jul 2026. Below you'll find Jan Willem Koelmans's most-played openings with White and Black, career performance record, notable wins and top events — everything you need to scout Jan Willem Koelmans 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 | 1,787 | 2,050 | Jan 2010 |
| Rapid | 1,822 | 1,832 | Jan 2025 |
| Blitz | 1,894 | 1,966 | Jun 2025 |
Performance record
| Split | Games | Wins | Draws | Losses | Win rate |
|---|---|---|---|---|---|
| Overall | 85 | 24 | 34 | 27 | 28.2% |
| As White | 42 | 15 | 19 | 8 | 35.7% |
| As Black | 43 | 9 | 15 | 19 | 20.9% |
Move-by-move preparation stats
Straight from the preparation tree built over all of Jan Willem Koelmans's games — the same tree the interactive prep board lets you walk to any depth. Scores are from Jan Willem Koelmans's side.
First moves as White (42 games)
| Move | Games | Share | Player score |
|---|---|---|---|
| d4 | 40 | 95.2% | 57.5% |
| Nf3 | 2 | 4.8% | 75.0% |
Main lines as White
- 1.d4 — 95% of White games, 57.5% score
- …Nf6 (40% of these games) — Koelmans usually continues c4 (56.3% score)
- …d5 (35% of these games) — Koelmans usually continues c4 (60.7% score)
- …f5 (10% of these games) — Koelmans usually continues g3 (66.7% score)
- 1.Nf3 — 5% of White games, 75.0% score
- …d6 (50% of these games) — Koelmans usually continues d4 (50.0% score)
- …Nf6 (50% of these games) — Koelmans usually continues d4 (100.0% score)
As Black against 1.e4 (18 games)
| Move | Games | Share | Player score |
|---|---|---|---|
| c5 | 18 | 100.0% | 30.6% |
As Black against 1.d4 (18 games)
| Move | Games | Share | Player score |
|---|---|---|---|
| d5 | 16 | 88.9% | 40.6% |
| e6 | 1 | 5.6% | 0.0% |
| Nf6 | 1 | 5.6% | 50.0% |
Jan Willem Koelmans's chess games
All 85 games by Jan Willem Koelmans in the Chess.ceo database (Oct 2003 - Jul 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: 24 wins, 34 draws, 27 losses.
Openings as White
| ECO | Opening | Games | W/D/L | Win rate |
|---|---|---|---|---|
| A57 | Benoni Defense | 6 | 1/3/2 | 16.7% |
| D18 | Slav Defense | 6 | 2/2/2 | 33.3% |
| A87 | Dutch Defense | 4 | 2/2/0 | 50.0% |
| D43 | Semi-Slav Defense | 4 | 3/1/0 | 75.0% |
| A50 | Indian Defense | 4 | 2/2/0 | 50.0% |
| E43 | Nimzo-Indian: Rubinstein System | 3 | 2/1/0 | 66.7% |
| A40 | Modern Defense | 3 | 1/1/1 | 33.3% |
| D11 | Queen's Gambit Accepted | 3 | 1/2/0 | 33.3% |
| E94 | King's Indian Defense: Orthodox Variation | 2 | 0/1/1 | 0.0% |
| D85 | Grünfeld Defense | 2 | 1/0/1 | 50.0% |
Openings as Black
| ECO | Opening | Games | W/D/L | Win rate |
|---|---|---|---|---|
| D15 | Slav Defense | 10 | 2/4/4 | 20.0% |
| A04 | Sicilian | 8 | 0/5/3 | 0.0% |
| B85 | Sicilian: Najdorf | 5 | 0/1/4 | 0.0% |
| D02 | London System | 2 | 1/0/1 | 50.0% |
| D04 | Colle System | 2 | 0/1/1 | 0.0% |
| A20 | English Opening: Reverse Sicilian | 2 | 0/1/1 | 0.0% |
| A11 | English Opening: Slav Setup | 2 | 1/1/0 | 50.0% |
| D35 | Semi-Slav Defense | 2 | 0/1/1 | 0.0% |
| B23 | Sicilian: Closed | 2 | 2/0/0 | 100.0% |
| B48 | Sicilian: Taimanov | 1 | 0/0/1 | 0.0% |
Notable wins
| Date | Opponent | Elo | Event | ECO |
|---|---|---|---|---|
| Jan 2009 | Patrick Lauferon | 2,249 | Val Thorens Open | D18 |
| Jan 2009 | Kinga Kiss | 2,146 | Val Thorens Open | E50 |
| Oct 2007 | Andrea La Manna | 2,145 | 29th Arco Open | A87 |
| Oct 2007 | Mariano Cardilli | 2,100 | 29th Arco Open | D18 |
| May 2015 | Spiros Orestis Alexopoulos | 1,953 | 9th Maastricht Limburg Open B | A12 |
Top events
| Event | Year | Games | Score | TPR |
|---|---|---|---|---|
| 29th Arco Open | 2007 | 9 | 5 | 2,135 |
| 11th Leiden LCT Open B | 2017 | 8 | 5 | 1,870 |
| 8th Maastricht Limburg Open B | 2014 | 7 | 3.5 | 1,880 |
| 5th Maastricht Limburg Open B | 2011 | 7 | 4.5 | 1,956 |
| 13th Vlissingen HZ Open | 2009 | 7 | 3 | 2,105 |
| 9th Maastricht Limburg Open B | 2015 | 7 | 5 | 2,075 |
| 7th Maastricht Limburg Open B | 2013 | 7 | 4 | 1,904 |
| 6th Maastricht Limburg Open B | 2012 | 7 | 3.5 | 1,855 |
Interactive opening tree from all 85 games, weak-spot detection and engine analysis.
Start preparationFrequently asked questions
Where can I find Jan Willem Koelmans's chess games?
85 games by Jan Willem Koelmans, from Oct 2003 to Jul 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 Jan Willem Koelmans has played.
What does Jan Willem Koelmans play on the first move as White?
Across 42 games with White in our database, Jan Willem Koelmans opens with 1.d4 (95% of games), 1.Nf3 (5% of games). Against 1.e4 as Black, Jan Willem Koelmans answers 1...c5 (100% of games). Against 1.d4: 1...d5 (89% of games), 1...e6 (6% of games), 1...Nf6 (6% of games).
What openings does Jan Willem Koelmans play as White?
As White, Jan Willem Koelmans's most-played openings in our database are: Benoni Defense (6 games, 16.7% win rate); Slav Defense (6 games, 33.3% win rate); Dutch Defense (4 games, 50.0% win rate). The full breakdown of 42 games with White is in the table above.
What openings does Jan Willem Koelmans play as Black?
As Black, Jan Willem Koelmans most often plays: Slav Defense (10 games, 20.0% win rate); Sicilian (8 games, 0.0% win rate); Sicilian: Najdorf (5 games, 0.0% win rate). See the table above for the top ten Black openings across 43 games.
What is Jan Willem Koelmans's FIDE rating?
Jan Willem Koelmans is currently rated 1,787 in classical chess, 1,822 in rapid and 1,894 in blitz. Peak classical rating: 2,050 (Jan 2010).
How many games has Jan Willem Koelmans played?
Our database contains 85 games by Jan Willem Koelmans, covering Oct 2003 to Jul 2026. Overall record: 24 wins, 34 draws, 27 losses (28.2% win rate).
How do I prepare against Jan Willem Koelmans?
85 games by Jan Willem Koelmans 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.