There re many different kinds of cukes. Some are short and fat. Others are longer. What is the name of the cucumber variety on the package? Cukes need lots of sun, fertile soil, and watering.

I think it has a lot to do with variety, sometimes with conditions, and how carefully/frequently you keep them picked. I immediately pick any cukes I find growing too fat or misshapen. However, I switched to 'Muncher' several years and it's my absolute favorite for producing nearly perfect cucumbers almost every time. I also tried 'Long Green' and had some good years with it, and some bad. I only had one bad year with Muncher, so I've settled on it.

response to party-music50 where did you get the seeds?

I bought them at the local Ace Hardware, but I just did a search and see that they're available on-line from several different seed sources.