Here is a fun sweep.  The spider guard is not as popular as it was 10-15 years ago.  Some say that it is an outdated guard because it is so easy to pass.  It is not as competitive as some other sport guard variations but because of the lack of teaching it and because it is not as popular anymore, it can be effective just because newer opponents are not used to seeing it.  Because of it's simplicity to learn, it is still good for newer practitioners that want to compete in sport BJJ.