As fantasy owners we're all looking for starting pitchers who strikeout a lot of batters. This has become even more apparent because in the past 20 seasons strikeout percentages have increased 15% in that time. Everyone has their own statistical threshold of what constitutes the strikeout percentage baseline they want to target with starting pitchers; I personally want pitchers who strikeout at least 20% of the batters they face. The table below provides a statistical breakdown by tier of strikeout percentages and strikeouts per nine. More detailed tables can be found in my fantasy guide.
However, in scouting circles not every strikeout is valued exactly the same. For example, what's more impressive, a swinging strikeout or a batter caught looking? A swinging strikeout (missing bats) implies the pitchers stuff (pitches) were so good the batter couldn't make contact. By good, the pitch has one or a combination of a fast velocity and/or a lot of vertical and horizontal movement. I love velocity, but it's not mandatory for missing a lot bats. R.A. Dickey was 11th in the league (among starting pitchers) in swing and miss (whiff) percentage and his knuckleball was thrown with an average velocity of 77 mph last season. If a batter is caught looking it suggests the batter was deceived by the pitch. Deception can be created by the pitchers delivery and/or throwing a pitch the batter did not expect.
In general scouts prefer pitchers who can miss a lot of bats with their stuff because pitchers who rely on deception have a lower probability of sustaining their performance year over year. But does how a pitcher generates strikeouts effect how fantasy owners evaluate them? I wondered is there any difference in fantasy value between pitchers who strikeout batters with deception vs. swings and misses.
I compiled data for every starting pitcher with at least two games started (per year) since 2008. Based on each their strikeout and whiff percentages I assigned a rating based on historical averages from the last two seasons. The table below provides a breakdown on whiff percentage. For example, Matt Harvey in 2012 struck out 28.57% batters and earned an "Excellent" designation. Also, he had a whiff rate of 26.82% which qualified for an "Great" designation. Then I combined both designations and summarized each player's statistics. For example, Harvey's final designation was "Excellent - Great."
Not surprisingly the top three pitcher types with the lowest ERA, WHIP, OPS and batting average against were the pitchers with Excellent strikeout rates. However, pitchers with the Excellent whiff rate along with the Excellent strikeout rate performed, only slightly, worse than the pitchers with either Great or Above Average strikeout rates. That seems counterintuitive to me. Why would pitchers with better stuff not have the best results? Two reasons: A) they walked more batters (9.01%), which is one percentage more. B) They gave up more home runs; specifically their HR/9 rate was 0.82 compared to only 0.65 and 0.75 for the Excellent - Above Average and Excellent - Great pitchers. Basically, pitchers with Excellent strikeout and whiff rates were more susceptible to allowing more runs because they allowed more home runs and allowed hitters to get on base more.
Not all strikeouts are the same, but when it comes to player evaluation from a fantasy standpoint, strikeouts are the same. In order to perform well, fantasy owners are going to need pitchers who strikeout a lot of hitters. However, it's important to find pitchers who can minimize the number of runs they allow by not walking a lot of hitters and giving up a lot of home runs.