Bicycle Tutor

I have a 10 speed cassette, a 10 speed shifters and a 9 speed derailleur. All are campagnolo centaur. I didnt even realize that i had a difference in speeds until my chain broke the other day and i took a closer look (Bought a complete bike off of classifieds last year). My question is: do I need to make sure that derailleur matches that speeds of the shifter of it doesnt really matter? The reason why I ask is when i shift, it seems that the derailleur is making 10 shifts, not 9.

Thank you in advance

Doesn't make a difference, since it's the shifter who's giving you 10 speed... You rear derailleur only follow the cable position that the shifter is onto...

Yeah, I figured as much: was just wondering why there is speed marking on the derailleur at all then? I thought that maybe "9 speed" on the derailleur meant "up to 9 speed", and since I had a 10 sp shifter/cassette, thoguth it may be a bit of an issue. Thank you anyways!

Most 9spd derailers can do 10 gears. like there are 5,6,7 deraillers that say they only do one speed.