Some tulips flowered others didn't

I have some Tulips that flowered and others that didn't in close proximity of each other. I bought this house 3 years ago and they were already there. The same thing happened last year. Are the bulbs shot ?

Doug says that it sounds as if some of the bulbs aren't happy with how you're growing them or how they have been grown. So in general, I'd either change the way you're growing them (see the articles here on how to grow tulips) or I'd dig them out and start again.

If you don't change the way you're growing, then I suspect this will happen every two to three years.