So Beethoven and Rachmaninoff were both left handed, and many people think that Chopin and Mozart were also left handed.

Do you think there was any correlation between their left handed ness and their virtuosity at piano?
Or is it just coincidence?
What are your thoughts?

I know lots of people disagree with me on this, but I reckon left handed people have the advantage when it comes to playing (difficult) music on the piano. Because a lot of music is mainly right-handed, it means that right-handed pianists get a super amazing right hand, but their left hand is left behind and struggles coordination and generally control-wise. If you were left-handed, you'd spend ages training your right hand because you have to, but would also have the natural control over your left hand that right-handed pianists don't, making difficult music with much more balanced hands not quite as bad.

I'm left handed but my right hand is still the dominant one when playing piano.

I have read lots of books about Beethoven (and thankfully there are still lots more to be read! ). I've yet to read anywhere that he wrote with his left hand. I think it's something that would have been mentioned if it were correct. However...studies of his signature say that the flow of ink, and the way the letters break off, could only have been made by a left hander.

It's possible that he might have been forced to write with his right hand as a child (by his father perhaps?) and resorted to using his dominant left hand when his father died. It's a question that has been debated many times.

I'm not sure if left handedness would make their virtuosity any better than right handed pianists. Beethoven was extremely heavy-handed on the piano and broke many strings because of this. He also preferred to compose, rather than perform, piano music.