Why is it that my offense have about 18 plays in which they are 100% (or near enough) familiar yet the Defense haven't got any. The top 3 are around 50-60%!!

Is that something about the plays I've chosen in this first 1.5 seasons or something generic about this game? Or something about my coaches?

jh

To me it seems like defense gets their familiarity much more slowly.

Your coaching staff has plays familiar to them.