Welcome to another edition of ‘The Fantasy Detective’ article series, where we will take a look at whether or not QB improvisation impacts fantasy performance. We will be using fantasy WAR as our fantasy performance metric.
What is QB improvisation? For every passing play, a QB’s improvisation is equal to 1 – xpass (expected pass % before the snap). This gives us a measure of how predictable QBs are, and likely gives us an idea of which QBs have high audible rates (a higher improvisation value means it is likely the QB called an audible).
Below we see QB average improvisation per dropback vs. fantasy WAR. There is a slight positive correlation, but not enough to really grab our attention.
While the results aren’t stunning, the graph does look fairly correlated (barring two outliers). Who are these outliers? Case Keenum and Colt McCoy, two non-starters who totaled less than 200 dropbacks combined last season. Let’s remove them and see what we get.
Wow! These results are much better. There is an evident correlation between high QB improvisation and fantasy WAR–48% of the variance in fantasy WAR is caused by variation in average improvisation on dropbacks.
When we remove dropbacks where QBs scramble, the results are even stronger. We see below that 53% of the variance in fantasy WAR is described by the variation in QB improvisations on pass attempts.
When we remove pass attempts and look at just dropbacks resulting in scrambles, there is little or correlation to fantasy WAR.
Why is any of this important? It helps us classify the best fantasy QBs based on two factors:
- Improvisation frequency–how often a given QB calls audibles and throws the defense off by running plays they don’t expect
- Offensive line skill/pocket awareness–it is apparent that when a QB is scrambling (more often than not due to the pocket collapsing) this correlation goes out the window. Hence, for their improvised play-calling to work, they need a strong O-line
Now that we see how important QB improvisation per pass attempt is, we can take a look at the improvisation rankings from 2021.
That’s all for this article. Stay tuned for more from ‘The Fantasy Detective’ series soon!