Do Ground Balls Matter?
There are not many things in baseball less exciting than ground-ball pitchers, especially low-strikeout ground-ball pitchers. Everyone wants to see home runs and strikeouts, but those are not always the most effective things. A lot of pitchers have had successful careers with underwhelming stuff by keeping the ball on the ground. The quickest way for hitters to do damage both in real life and in DFS is with extra-base hits. Ground balls almost never go for extra-base hits, although they do go for singles more often than fly balls do.
The league-average ground ball rate is around 44 to 45 percent, and anything over 50 percent would be considered a ground ball pitcher.
A look at the 2014 numbers shows that everything you would think about ground balls versus fly balls holds true. Ground balls go for hits more often than fly balls:
The Major League batting average on ground balls was .239
The Major League batting average on fly balls was .207
However, because ground balls tend to go for singles while fly balls tend to go for extra-base hits:
The Major League isolated slugging on ground balls was .020
The Major League isolated slugging on fly balls was .378
That huge difference in isolated slugging is a strong reason why you should not play against ground-ball pitchers in tournaments where you need extra-base hits, namely home runs, to win.
What I want to look at is whether or not high ground-ball pitchers allow enough additional hits on singles to make up for the difference in lack of extra-base hits.
We’re going to look at the list of the 10 highest ground ball versus fly ball pitchers from 2014 and the following data: ground-ball percentage (GB%), strikeout percentage (K%), batting average on balls in play (BABIP), and hits per inning (H/IP). Home runs count as hits, so this is not just looking at singles; this is all hits combined. There are a lot of numbers here, but there is some very useful information to see, so take a look through these two lists and think about what you see before reading on.
2014 Highest Ground Ball Rates
Dallas Keuchel: 63.5 GB%, 18.1 K%, .295 BABIP, 0.94 H/IP
Tyson Ross: 57.0 GB%, 24.0 K%, .291 BABIP, 0.84 H/IP
Felix Hernandez: 56.2 GB%, 27.2 K%, .258 BABIP, 0.72 H/IP
Alex Cobb: 56.2 GB%, 21.9 K%, .282 BABIP, 0.85 H/IP
Sonny Gray: 55.9 GB%, 20.4 K%, .277 BABIP, 0.85 H/IP
Francisco Liriano: 54.4 GB%, 25.3 K%, .280 BABIP, 0.80 H/IP
Kyle Gibson: 54.4 GB%, 14.1 K%, .287 BABIP, 0.99 H/IP
Zack Wheeler: 54.0 GB%, 23.6 K%, .304 BABIP, 0.90 H/IP
Henderson Alvarez: 53.8 GB%, 14.4 K%, .304 BABIP, 1.06 H/IP
Wily Peralta: 53.6 GB%, 18.4 K%, .295 BABIP, 1.0 H/IP
2014 Lowest Ground Ball Rates
Jake Odorizzi: 29.9 GB%, 24.2 K%, .295 BABIP, 0.93 H/IP
Jered Weaver: 32.9 GB%, 19.0 K%, .267 BABIP, 0.90 H/IP
Colby Lewis: 33.0 GB%, 17.5 K%, .339 BABIP, 1.24 H/IP
Travis Wood: 34.4 GB%, 18.7 K%, .320 BABIP, 1.09 H/IP
Julio Teheran: 34.8 GB%, 21.0 K%, .267 BABIP, 0.85 H/IP
Drew Hutchison: 36.1 GB%, 23.4 K%, .293 BABIP, 0.94 H/IP
Phil Hughes: 36.5 GB%, 21.8 K%, .324 BABIP, 1.05 H/IP
Max Scherzer: 36.7 GB%, 27.9 K%, .315 BABIP, 0.89 H/IP
Hector Noesi: 38.0 GB%, 16.8 K%, .290 BABIP, 1.04 H/IP
Jason Vargas: 38.3 GB%, 16.2 K%, .299 BABIP, 1.05 H/IP
When you look at hits per inning between the two lists, what do you notice? Let me break these lists down into some different groupings to better illustrate the important point.
Tyson Ross: 57.0 G%B, 24.0 K%, .291 BABIP, 0.84 H/IP
Felix Hernandez: 56.2 GB%, 27.2 K%, .258 BABIP, 0.72 H/IP
Francisco Liriano: 54.4 GB%, 25.3 K%, .280 BABIP, 0.80 H/IP
Kyle Gibson: 54.4 GB%, 14.1 K%, .287 BABIP, 0.99 H/IP
Henderson Alvarez: 53.8 GB%, 14.4 K%, .304 BABIP, 1.06 H/IP
Wily Peralta: 53.6 GB%, 18.4 K%, .295 BABIP, 1.00 H/IP
Jake Odorizzi: 29.9 GB%, 24.2 K%, .295 BABIP, 0.93 H/IP
Julio Teheran: 34.8 GB%, 21.0 K%, .267 BABIP, 0.85 H/IP
Drew Hutchison: 36.1 GB%, 23.4 K%, .293 BABIP, 0.94 H/IP
Colby Lewis: 33.0 GB%, 17.5 K%, .339 BABIP, 1.24 H/IP
Hector Noesi: 38.0 GB%, 16.8 K%, .290 BABIP, 1.04 H/IP
Jason Vargas: 38.3 GB%, 16.2 K%, .299 BABIP, 1.05 H/IP
Look at the hits per innings of these four groups. What jumps out is that it is not the ground-ball percentage that has the most effect on number of hits allowed. It is strikeout rate. This confirms what we saw in the section on strikeouts. Though ground balls do go for hits more than fly balls, it is still unpredictable what happens to a ball in the field of play. The goal should not be to target players who are going to get any particular type of hits, but rather simply a higher percentage of balls put in play.
For a further look at how ground balls affect hits, I’m going to remove home runs from the equation. Since home runs are not technically “balls in play”, we want to confirm the idea that ground balls fall for hits more often on balls in play. I’ll break it up into pitchers who have similar strikeout rates, and look at non-home run hits per inning.
Dallas Keuchel vs. Jered Weaver, 2014
Strikeout Rate: Keuchel, 18.1 percent | Weaver, 19.0 percent
Ground-Ball Rate: Keuchel, 63.5 percent | Weaver, 32.9 percent
BABIP: Keuchel, .295 | Weaver, .267
Innings Pitched/Batters Faced/Non-Home Run Hits Allowed: Keuchel, 200 IP/808 BF/176 hits | Weaver, 213 IP/888 BF/166 hits
Hits Allowed (singles/doubles/triples)/Inning: Keuchel, 0.88 hits per inning pitched | Weaver, 0.77 hits per inning pitched
Zack Wheeler vs Drew Hutchison 2014
Strikeout Rate: Wheeler 23.6 percent | Hutchison 23.4 percent
Ground-Ball Rate: Wheeler 54.0 percent | Hutchison 36.1 percent
BABIP: Wheeler, .304 | Hutchison, .293
Innings/Batters Faced/Non-Home Run Hits Allowed: Wheeler, 185 IP/794 BF/171 hits | Hutchison, 184 IP/786 BF/150 hits
Hits Allowed (singles/doubles/triples )/Inning: Wheeler, 0.92 H/IP | Hutchison, 0.81 H/IP.
These two data points do show that ground-ball pitchers allow more hits on balls in play, but in these examples, it works out to less than a hit per game. That is not enough of a boost to target these pitchers.
DFS Takeaways
This data confirms the strategy of avoiding playing against both high strikeout and high ground-ball pitchers in tournaments. In cash games, I am simply looking for hits. I will play against any low-strikeout pitcher, whether he allows ground balls or fly balls.