This formation is something special. I've always shied away from it because I didn't like how the backs were lined up. I thought "what's the need for the fullback if he doesn't lead block?". Well, now, I gotta say I love the potential of this formation, especially at running the ball!
I've found out that it has one of the best run/PA combo in the game: FB Belly/PA Slide.
FB Belly is an awesome run because, and I don't know why, the FB runs like CJ before the handoff. Therefore, he gets the ball like 1 yard behind the LOS, with the HB lead blocking, at full speed. This is an awesome run.
PA Slide is one of the best PA in the game IMO. It features the exact same animation as FB Belly. However, your QB rolls out to the right. The HB, after faking the block, runs to the right flat. It's cool now because you have your FB in the flat, the slot receiver running a deep out, the right WR running a bomb and the left WR coming in on a crossing route. With a scrambler, you can run it too.
Now, you'll probably ask "what happens if they stack the middle?". Well, that's where Split is nice; it has an answer to almost everything! In this case, you want to use the off tackle play. It's not as good as the usual one, but it's an effective outside run that'll get out of the inside stack. You also have, in some playbooks, HB Sweep that can be used.
Last, but not least, if the defense stacks the middle and overloads the right, what can you do? HAHA! That's where Quick Toss is used! This is not a good toss to use a lot because it's even more horizontal that FTTQT and it's very long to develop. However, if the D isn't there you're gooone.
After that, you have the passing game. The passing attack of this formation is pretty simple. It turns around your 2 backs. Most people say that the only way to stop a quick pass to the RB in the flat is by user defending this guy. But... what if there's 2 backs running to the flat? Ouch... Obviously, that's not the only thing you can do out of it. There are many passing plays that can be used. However, keep in mind that this is a running first formation and that you should have a passing formation included in your scheme to complement this.
Washington and (gonna make some people happy) Seattle have both 2 Split formations with many good plays in each. SF is the only playbook I've found the quick toss in.
Subject: Split formation 