Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Res. | Record | Opponent | Method | Round | Location |
| --- | --- | --- | --- | --- | --- |
| Win | 30-11-1 | Jordanas Poskaitis | Submission (leglock) | N/A | Vilnius , Lithuania |
| Win | 29-11-1 | Petrov Kolev | Submission (heel hook) | 1 | Lithuania |
| Loss | 28-11-1 | Quinton Jackson | Submission (strikes) | 1 | Yokohama , Japan |
| Win | 28-10-1 | Katsuhisa Fujii | Submission (guillotine choke) | 1 | Tokyo , Japan |
| Draw | 27-10-1 | Hiromitsu Kanehara | Draw | 3 | Yokohama , Japan |
| Loss | 27-10 | Bobby Hoffman | TKO (corner stoppage) | 2 | Tokyo , Japan |
| Win | 27-9 | Borislav Jeliazkov | Submission (armbar) | 2 | Yokohama , Japan |
| Win | 26-9 | Kestutis Smirnovas | Submission (achilles lock) | 1 | Lithuania |
| Win | 25-9 | Martin Lazarev | Decision (4-0 points) | 1 | Ekaterinburg , Russia |
| Loss | 24-9 | Tsuyoshi Kohsaka | KO (punches) | 2 | Osaka , Japan |
| Win | 24-8 | Valerijus Golubovskis | Submission (arm lock) | N/A | Lithuania |
| Win | 23-8 | Bakouri Gogitidze | Submission (ankle lock) | 1 | Russia |
| Win | 22-8 | Emil Kristev | Submission (Achilles Lock) | 1 | Tula, Russia |
| Win | 21-8 | Lee Hasdell | Decision | 3 | Ekaterinburg , Russia |
| Loss | 20-8 | Renato Sobral | Submission (armbar) | 3 | Tokyo , Japan |
| Win | 20-7 | Brad Kohler | Submission (armbar) | 1 | Tokyo , Japan |
| Win | 19-7 | Justin McCully | Technical Submission (achilles lock) | 1 | Tokyo , Japan |
| Loss | 18-7 | Bakouri Gogitidze | Submission | 1 | Georgia , United States |
| Win | 18-6 | Joop Kasteel | Submission (achilles lock) | 1 | Japan |
| Win | 17-6 | Randy Couture | Submission (kimura) | 1 | Tokyo , Japan |
| Win | 16-6 | Masayuki Naruse | Submission | 1 | Tokyo , Japan |
| Loss | 15-6 | Kiyoshi Tamura | Submission | 1 | Tokyo , Japan |
| Win | 15-5 | Volk Han | Submission | 1 | Fukuoka, Japan |
| Win | 14-5 | Tsuyoshi Kohsaka | Submission | 1 | Osaka, Japan |
| Win | 13-5 | Masayuki Naruse | Submission (ankle lock) | 1 | Tokyo , Japan |
| Loss | 12-5 | Tsuyoshi Kohsaka | Submission | 1 | Tokyo , Japan |
| Loss | 12-4 | Kiyoshi Tamura | Submission | 1 | Nagoya, Japan |
| Loss | 12-3 | Adilson Lima | Submission (armbar) | 1 | Tokyo , Japan |
| Win | 12-2 | Sidney Goncalves Freitas | Submission (chin in the eye) | 1 | Japan |
| Loss | 11-2 | Carlos Barreto | Submission (rear naked choke) | 2 | Japan |
| Win | 11-1 | Wataru Sakata | Submission | 1 | Tokyo , Japan |
| Loss | 10-1 | Ricardo Morais | Submission (rear naked choke) | 1 | Moscow , Russia |
| Win | 10-0 | Achmed Sagidgusenov | Submission (achilles lock) | 1 | Moscow , Russia |
| Win | 9-0 | Igor Vovchanchyn | Submission (chin in the eye) | 1 | Moscow , Russia |
| Win | 8-0 | Andrei Besedin | Submission (guillotine choke) | 1 | Moscow , Russia |
| Win | 7-0 | Zagil Eribinov | Submission (armbar) | 1 | Moscow , Russia |
| Win | 6-0 | Nikolai Zouev | Submission | 1 | Fukuoka, Japan |
| Win | 5-0 | Victor Yerohin | Submission (rear naked choke) | 1 | Moscow , Russia |
| Win | 4-0 | Leonid Efremov | Submission (achilles lock) | 1 | Moscow , Russia |
| Win | 3-0 | Vadim Shevchenko | Submission (achilles lock) | 1 | Moscow , Russia |
| Win | 2-0 | Maxim Tarasov | Submission (achilles lock) | 1 | Moscow , Russia |
| Win | 1-0 | Piotr Tjernov | Submission (achilles lock) | 1 | Moscow , Russia |
Question:
What was the method of resolution when Mikhail Ilyukhin's record was 4-0?
Answer:
Submission (achilles lock)