Smagin earned the title of International Master in 1982, and Grandmaster in 1985. He is a four-time winner of the Moscow Chess Championship, with victories in 1981, 1983, 1986, and 1991. Additionally, he won the prestigious Aeroflot Open in Moscow in 2002.
His career also includes successful performances in various international tournaments. Some notable wins include the Gausdal Classics in 1992, the Capablanca Memorial in 1998, the Olomouc International round-robin tournament in 1999, and the Załakaros Open in 2001.
Although primarily a player, Smagin has also been a chess coach. He has worked with the Chess Federation of Armenia, as the head coach of the women’s national team, and with the International Chess Federation (FIDE) as a senior trainer.