user: Question: What is the average rebounds for the player who started in 1986 and who plays SG?
Columns: ['Player', 'Pos.', 'From', 'School/Country', 'Rebs', 'Asts']
Types: ['text', 'text', 'real', 'text', 'real', 'real']
Sample row: ['Rubén Garcés Category:Articles with hCards', 'PF', 2000.0, 'Providence', 22.0, 4.0]
SQL:

assistant: SELECT AVG("Rebs") FROM "Table" WHERE "From" = 1986.0 AND "Pos." = 'SG';