| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 401. C Garcia Palermo vs A Kosten |
| ½-½ | 47 | 1989 | Forli Open | B06 Robatsch |
| 402. A Kosten vs S Tatai |
| ½-½ | 30 | 1989 | Forli Open | B87 Sicilian, Fischer-Sozin with ...a6 and ...b5 |
| 403. A Kosten vs G Laco |
| 1-0 | 53 | 1989 | Forli Open | B45 Sicilian, Taimanov |
| 404. Taimanov vs A Kosten |
| 0-1 | 65 | 1989 | Forli Open | A04 Reti Opening |
| 405. S Mohr vs A Kosten |
| 0-1 | 61 | 1989 | Altensteig | B07 Pirc |
| 406. A Kosten vs Lputian |
| 0-1 | 44 | 1989 | Altensteig | C02 French, Advance |
| 407. M Wahls vs A Kosten |
| 1-0 | 43 | 1989 | Altensteig | B14 Caro-Kann, Panov-Botvinnik Attack |
| 408. M Stangl vs A Kosten |
| 0-1 | 48 | 1989 | Altensteig | A04 Reti Opening |
| 409. A Kosten vs N Luecke |
| 1-0 | 40 | 1989 | Altensteig | B33 Sicilian |
| 410. A Kosten vs R Lau |
| 0-1 | 45 | 1989 | Altensteig | B06 Robatsch |
| 411. A Kosten vs L Brunner |
| 1-0 | 42 | 1989 | Altensteig | C02 French, Advance |
| 412. A Kosten vs K Bischoff |
| 1-0 | 34 | 1989 | Altensteig | B32 Sicilian |
| 413. S Kindermann vs A Kosten |
| ½-½ | 17 | 1989 | Altensteig | C91 Ruy Lopez, Closed |
| 414. A Kosten vs Adorjan |
| ½-½ | 19 | 1989 | Altensteig | B82 Sicilian, Scheveningen |
| 415. A Kosten vs J Emms |
| ½-½ | 39 | 1989 | British Championship | C53 Giuoco Piano |
| 416. J G Nicholson vs A Kosten |
| ½-½ | 32 | 1989 | British Championship | B06 Robatsch |
| 417. A Kosten vs S Cullip |
| 0-1 | 72 | 1989 | British Championship | B42 Sicilian, Kan |
| 418. M Surtees vs A Kosten |
| 0-1 | 30 | 1989 | British Championship | B06 Robatsch |
| 419. A Kosten vs N Carr |
| 1-0 | 31 | 1989 | British Championship | B06 Robatsch |
| 420. P J Morris vs A Kosten |
| 1-0 | 50 | 1989 | British Championship | B06 Robatsch |
| 421. A Kosten vs A Collinson |
| 1-0 | 37 | 1989 | British Championship | B93 Sicilian, Najdorf, 6.f4 |
| 422. C Ward vs A Kosten |
| ½-½ | 45 | 1989 | British Championship | A41 Queen's Pawn Game (with ...d6) |
| 423. A Kosten vs J Cavendish |
| 1-0 | 40 | 1989 | British Championship | B32 Sicilian |
| 424. G Flear vs A Kosten |
| 1-0 | 41 | 1989 | British Championship | E20 Nimzo-Indian |
| 425. A Kosten vs L Chachere |
| ½-½ | 43 | 1989 | 13th Lloyds Bank Masters Open | B93 Sicilian, Najdorf, 6.f4 |
Kibitzing
