Well first let me to say Welcome to trap17, whyte-knight. I assume that you have great interest in the graphic and design? Well welcome and Enjoy looking at the forums to find other cool stuffs such as yours, discuss things, ask queries, and other enjoyable things to do (though i'm sure that you won't find any of my useful post here)
Back to your sigs above, i think they're o-kay. Well i don't really into sports and i don't know any of them, but the design is okay. There are much room to add improvement though, so maybe you can try to ask someone more experienced here or looking at the others works to find more inspiration