I intend to do a lot more with success rate this season than I have in the past. The more I think about it, the more I like it. In preparation for using success rate more, I made a video on what exactly it is and why it's great. The transcript of the video is below.
A great football stat that you may not have heard of is success rate. It's pretty simple: it aims to tell you what percentage of a team's plays were a success.
So what counts as a success? On first down, it means gaining at least 50% of the yards to go. On second down, it means gaining at least 70% of yards to go. On third and fourth down, it means gaining 100% of yards to go. You’ve actually been tracking success rate on third and fourth down forever; you just call it third and fourth down conversions.
The average success rate for all of college football is in the low 40s, while in a single game, success rate can vary from the 80s to zero at the extremes.
The reason why success rate is better than something like yards per play is because it gives you context for each play. Rushing for 8 yards is usually a good run, but if it's on third-and-15, well, that's not so great. That run will push up a running back's yards per carry, but it won't impress success rate. Meanwhile, a gain of two on second-and-one will drop yards per carry, but success rate will credit it as the good play that it was.
Here is a larger example of where success rate can come in handy. Will Muschamp was trying to save his job in 2014 with new offensive coordinator hire Kurt Roper. In Florida’s first game, the Gators beat Eastern Michigan 65-0. All of the conventional stats said this was a good game. The Gators gained 655 yards at a 7.6 per play clip.
Before the game entered what Football Outsiders considers garbage time, Jeff Driskel completed 85% of his passes for 135 yards with no picks. [UPDATE: There is an error here. He actually completed 17/21 for 81%. This doesn't change any of the point of all this.] The yards per attempt is a bit low, but Roper likes to employ screens and swing passes that tend to push that number lower. It looks good, right?
Well, not according to success rate. Driskel’s success rate in this portion of the game was a dismal 28.6%, which should have been a huge red flag. If his success rate against Eastern Michigan’s starters was this low, how was it going to get better against SEC starters? Driskel would end up losing his starting job to a true freshman later in the season. The offense as a whole faltered and Muschamp was out of a job. While the scoreboard told you that Florida had a great day against Eastern Michigan, success rate told you that the team was in trouble.
Success rate alone won’t tell you everything you need to know, but it’s an important part of a modern analytical toolbox. It’s time to start keeping track of it on more than just third and fourth downs.