JK

Jan Koolstra

Rated since January 2023

1585 Rapid

RIVALRY

Nemesis
Looman, J.F.M. (Hans)
Games: 6 · Win rate: 50%
Kryptonite
Koolstra, J. (Jacques)
Games: 5 · Win rate: 0%
Easy Target
Kraay, J. (Jos)
Games: 6 · Win rate: 100%

The good & the bad

Best wins
VELLEKOOP, A. (ALFRED) 1735
11208 S.V. EsPion interne competitie 31-03-2025 t/m 28-04-2025 (080015) · Monday 31 March 2025
KOK, P. (PIETER) 1702
8654 EsPion interne competitie 2023-2024 Voorjaar ronde 2-5 · Monday 11 March 2024
MANK, A.H.C. (AD) 1666
8654 EsPion interne competitie 2023-2024 Voorjaar ronde 2-5 · Monday 26 February 2024
KIPS, D. (DAVID) 1658
11675 S.V. EsPion interne competitie 30-06-2025 t/m 21-07-2025 (080015) · Monday 7 July 2025
TJONG-AKIET, R. (RAF) 1644
6637 EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 1 - 3 · Monday 6 February 2023
Worst losses
HILLEBRAND, J.B.N.M. (JOS) 1348
8119 EsPion interne competitie 2023-2024 Ronde 9 - 11 · Monday 4 December 2023
SCHALEKAMP, R. (ROB) 1442
6271 EsPion Interne competitie 2022-2023 Najaar 2022 ronde 10-13 · Monday 19 December 2022
PLANTFEBER, H.J. (HENK) 1468
6784 EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 4 - 7 · Monday 27 February 2023
MERKUL, E. (EUGEN) 1476
8309 EsPion interne competitie 2023-2024 Ronde 12 - 14 · Monday 15 January 2024
SIEWERTSEN, K. (KLAAS) 1503
13647 SGA Competitie 2025-2026 Viertallen ronde 6 en 7 · Monday 30 March 2026
No FIDE-rated tournaments found.
S.V. EsPion interne competitie 11-05-2026 t/m 25-05-2026 (080015) Monday 2 February 2026 +0–1=0 -7.5
S.V. EsPion interne competitie 31-03-2026 t/m 20-04-2026 (080015) Monday 2 February 2026 +1–0=1 +11.8
S.V. EsPion interne competitie 02-03-2026 t/m 23-03-2026 (080015) Monday 2 February 2026 +1–2=0 -6.9
S.V. EsPion interne competitie 02-02-2026 t/m 23-02-2026 (080015) Monday 2 February 2026 +1–2=0 -8.3
SGA Competitie 2025-2026 Viertallen ronde 6 en 7 Wednesday 1 October 2025 +0–1=0 -16.1
S.V. EsPion interne competitie 05-01-2026 t/m 26-01-2026 (080015) Monday 22 September 2025 +1–1=0 -7.9
S.V. EsPion interne competitie 01-12-2025 t/m 22-12-2025 (080015) Monday 22 September 2025 +1–0=1 +6.5
S.V. EsPion interne competitie 03-11-2025 t/m 24-11-2025 (080015) Monday 22 September 2025 +0–1=2 -7.9
S.V. EsPion interne competitie 29-09-2025 t/m 27-10-2025 (080015) Monday 22 September 2025 +1–2=0 +0.1
S.V. EsPion interne competitie 22-09-2025 t/m 22-09-2025 (080015) Monday 22 September 2025 +0–0=1 +6.6
S.V. EsPion interne competitie 28-07-2025 t/m 25-08-2025 (080015) Monday 2 June 2025 +1–6=0 -47.2
S.V. EsPion interne competitie 30-06-2025 t/m 21-07-2025 (080015) Monday 2 June 2025 +3–2=0 +3.7
S.V. EsPion interne competitie 02-06-2025 t/m 23-06-2025 (080015) Monday 2 June 2025 +4–1=1 +11.2
S.V. EsPion interne competitie 12-05-2025 t/m 26-05-2025 (080015) Monday 3 February 2025 +1–1=1 +4.2
S.V. EsPion interne competitie 31-03-2025 t/m 28-04-2025 (080015) Monday 3 February 2025 +1–2=0 +5.8
S.V. EsPion interne competitie 03-03-2025 t/m 24-03-2025 (080015) Monday 3 February 2025 +1–1=0 -1.0
S.V. EsPion interne competitie 03-02-2025 t/m 24-02-2025 (080015) Monday 3 February 2025 +1–2=1 +2.0
S.V. EsPion interne competitie 27-01-2025 t/m 27-01-2025 (080015) Monday 23 September 2024 +1–0=0 +9.6
S.V. EsPion interne competitie 06-01-2025 t/m 20-01-2025 (080015) Monday 23 September 2024 +1–1=0 -2.7
S.V. EsPion interne competitie 28-10-2024 t/m 23-12-2024 (080015) Monday 23 September 2024 +2–4=3 -23.2
S.V. EsPion interne competitie 23-09-2024 t/m 21-10-2024 (080015) Monday 23 September 2024 +0–2=1 -11.4
EsPion interne competitie 2023-2024 Voorjaar ronde 15-17 Monday 2 October 2023 +1–0=1 +9.7
EsPion interne competitie 2023-2024 Voorjaar ronde 11-14 Monday 2 October 2023 +1–1=1 -10.6
EsPion interne competitie 2023-2024 Voorjaar ronde 6-10 Monday 2 October 2023 +0–2=1 -15.8
EsPion interne competitie 2023-2024 Voorjaar ronde 2-5 Monday 2 October 2023 +2–2=0 +21.9
EsPion interne competitie 2023-2024 Ronde 15 - 17 Monday 2 October 2023 +1–1=0 -8.1
EsPion interne competitie 2023-2024 Ronde 12 - 14 Monday 2 October 2023 +1–2=0 -17.6
EsPion interne competitie 2023-2024 Ronde 9 - 11 Monday 2 October 2023 +1–1=1 -16.2
EsPion interne competitie 2023-2024 Ronde 5-8 Monday 2 October 2023 +1–1=0 +4.6
EsPion interne competitie 2023-2024 Ronde 1-4 Monday 2 October 2023 +1–1=0 +0.2
SGA Competitie 2022-2023 3e Klasse B ronde 3 Saturday 1 October 2022 +0–1=0
EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 17 Monday 26 September 2022 +0–0=1 +4.8
EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 13 - 16 Monday 26 September 2022 +2–2=0 +13.2
EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 8 - 12 Monday 26 September 2022 +0–1=2 +4.7
EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 4 - 7 Monday 26 September 2022 +2–1=1 +10.2
EsPion Interne competitie 2022-2023 Voorjaar 2023 ronde 1 - 3 Monday 26 September 2022 +1–1=0 +18.1
EsPion Interne competitie 2022-2023 Najaar 2022 Ronde 14-16 Monday 26 September 2022 +2–1=0 +8.4
EsPion Interne competitie 2022-2023 Najaar 2022 ronde 10-13 Monday 26 September 2022 +2–2=0 -10.1

Team Competition

Current team
EsPion 4
Viertallen · 2025-2026 · 2 games

Rating History

Loading rating history...

Peak Ratings

Classic 1650 April 1, 2024
Rapid 1632 Aug. 1, 2025
Blitz 1607 March 1, 2026

Games

Wins 40
Losses 52
Draws 20
Win Rate 36%

Performance by Color

Color Wins Draws Losses Win Rate
White 18 10 27 33%
Black 22 10 25 39%

Recent Matches

Ran, M. (Mart) (1747) Monday 18 May 2026 LOSS -7.5
Bezemer, C. (Casper) (1551) Monday 20 April 2026 DRAW -1.7
Stokman, L.N. (Lennart) (1628) Monday 13 April 2026 WIN +13.5
Siewertsen, K. (Klaas) (1503) Monday 30 March 2026 LOSS -16.1
Koopman, G.J.K. (Gabriella) (1451) Monday 23 March 2026 WIN +7.3
Koolstra, J. (Jacques) (1618) Monday 16 March 2026 LOSS -12.1
Dekker, C.C. (Casper) (2005) Monday 9 March 2026 LOSS -2.1
Wastiaux, R. (Roland) (1845) Monday 23 February 2026 LOSS -5.3
didac.peris Monday 16 February 2026 WIN
Velden van, R. (Rudolf) (1947) Monday 2 February 2026 LOSS -3.1
Calcar van, B.T. (Bas) (1225) Monday 19 January 2026 WIN +2.1
Mank, A.H.C. (Ad) (1697) Monday 12 January 2026 LOSS -10.0
Kerkhoff, F.C. (Frans) (1710) Monday 22 December 2025 DRAW +3.2
Jay, M.B. (Michael) (1296) Monday 15 December 2025 WIN +3.3
Golovinskii, A.G. (Aleksandr) Monday 24 November 2025 DRAW
Wieringa, E.A. (Ric) (1788) Monday 10 November 2025 DRAW +5.4
Vaassen, M. (Mick) (1601) Monday 3 November 2025 LOSS -13.3
Wastiaux, R. (Roland) (1810) Monday 27 October 2025 LOSS -6.4
Stolp, H.P. (Peter) (1541) Monday 13 October 2025 WIN +9.6
Winnubst, P. (Paul) (1954) Monday 6 October 2025 LOSS -3.1