restaining deck

Need advise on restaining my deck. the deck is at least 10 years old. I recently purchased the house and have no history of deck. From what I see, it has a solid stain on it today and I wish to redo it. My plan is to clean and wash deck, then apply a new solid stain. My question is whether I need to strip existing stain? I plan to match as closely as I can the current color. I am leaning towards a CABOT product, but would entertain BEHR as well. Do I have to strip the old stain, if I do not have the original stain paint code?

kt