In the conventional style, the lifter keeps the feet narrower than the shoulders and grips the bar outside the legs. In Eastern Europe this style is called “classic.”
The sumo stance is wider, and the arms are inside the knees at the start of the pull. Sumo stances range from narrow, with the arms crowded by the legs, to super wide, with the toes risking getting smashed by the plates.
The sumo versus conventional debate is decades old…and pointless. Historic world records have been brought down with both stances. Conventional: Andy Bolton, Lamar Gant, Konstantin Konstantinov... Sumo: Ed Coan, John Inzer, Max Podtinny…
The sumo’s main advantage is a shorter distance the bar has to travel.
The ace of trump of the classic stance is a higher level of arousal. Conventional pullers like Kirk Karwoski work themselves into a blind rage, something sumoists like Tom Eiseman cannot afford due to a greater precision demanded by a wider stance.
Every lifter has to find an individual answer to the question, “Which style is better?”
Generally, if you have a short back and are a “psych” lifter, the conventional style is your best bet. A composed lifter with a longer spine is most likely to succeed with sumo.