user: Question: How many editions have a most wins value of Franco Marvulli (4)?
Columns: ['Six at', 'Number of editions', 'First ridden', 'Last ridden', 'Most wins by']
Types: ['text', 'real', 'real', 'real', 'text']
Sample row: ['Adelaide (SA)', 6.0, 1960.0, 1967.0, 'Sid Patterson , Nino Solari (2)']
SQL:

assistant: SELECT COUNT("Number of editions") FROM "Table" WHERE "Most wins by" = 'Franco Marvulli (4)';