When submitting your sf or fantasy manuscript, do you believe you have a higher chance of success if you write a standalone, trilogy, or series?

Series (Examples: The Vorkosigan Saga by Lois McMaster Bujold, Song of Ice and Fire Series by George R.R. Martin) 50%

Standalone (Examples: The Martian by Andy Weir, Stardust by Neil Gaiman) 25%

Trilogy (Examples: The Foundation Trilogy by Isaac Asimov, Lord of The Rings by J. R. R. Tolkien) 25%