26th USSR Championship — Tbilisi 1959

Tigran Petrosian was born in Tbilisi, swept its streets as an orphaned teenager to survive the war years, and trained at its Palace of Pioneers before poverty sent him on to Yerevan and then Moscow. In 1959 he came back to his home city and won his first Soviet championship — 13½ points from 19 games, without losing a single one — in a 20-player field that chessgames.com counts as including more than ten past and future Soviet champions.

◇A return to Tbilisi

Petrosian was born in Tiflis (Tbilisi) in 1929 to Armenian parents; his father worked as a janitor, and after both parents died during the war years the teenage Petrosian swept the city's streets to earn a living. He had already begun training at the city's Palace of Pioneers under Archil Ebralidze, whose systematic, Nimzowitsch-influenced teaching — built around the study of My System and Chess Praxis — shaped the patient, prophylactic style that would define Petrosian's entire career.

He left for Yerevan in 1946 and then Moscow in 1949, working his way up the Soviet ranks through the 1950s. A decade after leaving, he returned to Tbilisi for the 26th Soviet Championship — and won it, the first of what became four Soviet titles.

◇Unbeaten among champions

Twenty players reached the final, drawn from semifinals at Baku, Moscow, Rostov and Tashkent. Petrosian went through all nineteen rounds without a loss — eight wins and eleven draws — to finish on 13½, a full point ahead of Mikhail Tal and Boris Spassky, who tied for second on 12½.

It was not the most points scored in the room, but it was the only score with no losses attached to it — the template for the rest of his career, and the tournament that first earned him the nickname 'Iron Tigran.'