This article is part of our The Saber's Edge series.
The public's disdain for flyball pitchers can be traced to two things: Common Sense and xFIP. Common sense tells us that a hitter is extremely unlikely to hit a home run on a groundball. The more a pitcher can generate groundballs, he will have better results.
Besides the age-old common sense, my previous boss, Dave Studeman, created xFIP a little more than 10 years ago. xFIP is an ERA estimator which uses strikeout, walk and flyball rate. The data mainly points to pitchers having a higher home runs rate as they allow more flyballs.
Heads up, I am going to stop right now using any mention of flyball rate. I find baseball full of too many stats already. Instead of memorizing cut-offs of flyball and groundball rate, I just use groundball rate. If you want to convert groundball rate (GB%) to flyball rate (FB%) use FB% = 80%-GB% with the other 20 percent going to line drives.
xFIP works for most pitchers with more than 75 percent of all pitchers having a groundball rate less than 40 percent and 87
The public's disdain for flyball pitchers can be traced to two things: Common Sense and xFIP. Common sense tells us that a hitter is extremely unlikely to hit a home run on a groundball. The more a pitcher can generate groundballs, he will have better results.
Besides the age-old common sense, my previous boss, Dave Studeman, created xFIP a little more than 10 years ago. xFIP is an ERA estimator which uses strikeout, walk and flyball rate. The data mainly points to pitchers having a higher home runs rate as they allow more flyballs.
Heads up, I am going to stop right now using any mention of flyball rate. I find baseball full of too many stats already. Instead of memorizing cut-offs of flyball and groundball rate, I just use groundball rate. If you want to convert groundball rate (GB%) to flyball rate (FB%) use FB% = 80%-GB% with the other 20 percent going to line drives.
xFIP works for most pitchers with more than 75 percent of all pitchers having a groundball rate less than 40 percent and 87 percent having a groundball rate less than 35 percent. The problem is heavy flyball pitchers start to see their BABIP drop below league average and their ERA constantly outperforms their xFIP (and FIP).
The reason for this change is that these low groundball pitchers produce a large percentage of pop outs, which can easily be caught for outs. The groundball pitchers will see about 30 percent of their grounders go randomly for hits. xFIP doesn't acknowledge this trait and projects the low GB% hitters to perform worse in the future, but these pitchers on average have a lower than expected ERA.
From my research, a groundball rate of 35 percent is when pitchers really begin to see a difference from their ERA to their FIP and xFIP. The problem this season is that only six regular starters meet these criteria of a strikeout rate more than 20 percent, a BB% less than 10 percent and a GB% less than 35 percent. I have gone ahead and expanded the list to pitchers with a GB% less than 40 percent and the list increases to 20. Here they are ordered by GB%.
| PLAYER | GB% | K% | BB% | IP | xFIP | FIP | ERA |
| Drew Smyly | 31.5 | 23.3 | 6.4 | 137.1 | 4.34 | 4.31 | 4.85 |
| A.J. Griffin | 31.9 | 20.3 | 8.9 | 84.2 | 4.89 | 5.3 | 4.68 |
| Max Scherzer | 33.4 | 32.2 | 6.3 | 167.2 | 3.3 | 3.36 | 2.95 |
| Ian Kennedy | 34.2 | 23.8 | 7.9 | 140.1 | 4.51 | 4.95 | 3.78 |
| Marco Estrada | 34.3 | 23.4 | 8.9 | 128.1 | 4.49 | 3.92 | 2.95 |
| Danny Duffy | 34.8 | 28.1 | 5.1 | 124.1 | 3.56 | 3.15 | 2.82 |
| Vince Velasquez | 35.5 | 26.6 | 9.1 | 107.1 | 3.84 | 3.77 | 3.94 |
| Justin Verlander | 35.7 | 26.3 | 6.7 | 160.1 | 3.92 | 3.49 | 3.42 |
| Matt Moore | 36.7 | 20.4 | 8.6 | 148 | 4.75 | 4.45 | 4.14 |
| Jake Odorizzi | 37.0 | 22.2 | 7.0 | 142.2 | 4.33 | 4.12 | 3.72 |
| Madison Bumgarner | 37.8 | 27.8 | 6.3 | 170.2 | 3.51 | 3.14 | 2.11 |
| Matt Shoemaker | 38.1 | 21.5 | 4.6 | 138.2 | 3.95 | 3.46 | 4.22 |
| Anibal Sanchez | 39.0 | 20.4 | 9.2 | 112.2 | 4.72 | 5.26 | 6.31 |
| Jose Quintana | 39.1 | 22.1 | 5.8 | 151.2 | 4.07 | 3.42 | 2.85 |
| Matt Boyd | 39.7 | 20.1 | 8.0 | 62.2 | 4.72 | 4.67 | 4.16 |
| Julio Teheran | 39.7 | 22.4 | 5.5 | 134.2 | 4.07 | 3.69 | 2.81 |
| Chris Sale | 39.7 | 24.5 | 5.5 | 160.2 | 3.71 | 3.48 | 3.3 |
| Jeremy Hellickson | 39.7 | 20.5 | 5.5 | 143 | 3.92 | 4.04 | 3.65 |
| Stephen Strasburg | 39.9 | 30.8 | 7.2 | 143.2 | 3.21 | 2.94 | 3.07 |
| Anthony DeSclafani | 39.9 | 21.4 | 6.1 | 72.1 | 4.06 | 3.92 | 3.11 |
Of these 20 pitchers, their average ERA is 0.30 less than their average FIP and 0.45 less than their average xFIP. While not all these pitcher will have a nice ERA or be fantasy relevant, a person should not shy away from them because of their flyball nature. Here are my thoughts on those with a GB% less than 35 percent.
Drew Smyly: Simply has given up too many home runs. These flyball pitchers will give up more home runs than average with the median number of home runs allowed at 1.15 HR/9. Smyly is at 1.57 HR/9 with most of the damage coming from his fastball.
One huge change from last season was his 28.0 K% with only an 11.4 percent swinging-strike rate. Normally, a pitcher's K% is twice his swinging-strike rate, so Smyly's K% should have been about 22.8 percent. This season, his swinging-strike rate is similar at 10.8 percent, which will work out to a 21.6 K%; he is at 23.3 percent. I don't even know if the low groundball rate makes him a fantasy asset and I understand owners who have moved on. He has shown some improvement in the season's second half with a 3.16 ERA and a reasonable 0.97 HR/9. I would not be surprised if his true talents around a 3.50 ERA.
A.J. Griffin: First, Griffin barely made both the K% and BB% cutoffs, so he's one of the worst pitchers on the list. Like Smyly, all his issues stem from allowing home runs (1.81 HR/9). I am giving him some slack since this is the first year he has thrown in the majors since 2013. He may get hit around more than he did previously because his fastball is down 1 to 2 mph compared to when he previously threw. I don't see any reason to roster him now or in the future.
Max Scherzer: His stats are finally in line with what to expect from a low groundball pitcher: High HR/9 (1.34), low BABIP (.245), ERA (2.95) lower than FIP (3.36) and xFIP (3.30). Scherzer is a fantasy stud and should be taken off the board as a top-10 pitcher and more likely top 5.
Ian Kennedy: I am a Royals fan and am tired of Kennedy discussions, so I am skipping him.
Marco Estrada: Estrada deals with home runs like the rest of these pitchers, but over the last two seasons, he has posted a .216 BABIP. With the low BABIP value this season, his ERA (2.92) is about a point lower than his FIP (3.92) and 1.5 points lower than his xFIP (4.49). I could see his ERA jump into the 3.50 range with some increase in HR/9 and BABIP.
Danny Duffy: Now as a Royals fan, I can talk Danny Duffy all day. The main reason for this turnaround is a new change and a slider he learned from Greg Holland. These two pitches have helped him post a 13.8 percent swinging-strike rate and a strikeout rate at 10 K/9. Besides the high strikeout rate, he has a career-low walk rate (1.81 BB/9). Duffy has always been a low groundball pitcher, so his ERA of 2.82 is lower than his other ERA estimators (3.15 FIP and 3.56 xFIP). Duffy has been a great surprise this summer.
