Cubs by the Numbers: Plate Discipline for Pitchers

In my last post, I showed how plate discipline metics highlight a hitter’s approach at the plate. Those numbers also give a window into a pitcher’s approach, providing a story of how he works and perhaps what needs to be adjusted for him to more effectively attack a hitter.

Here is how Fangraphs breaks down each stat, with the averages are at the end of the definition.

  • O-Swing% = Swings at pitches outside the zone / pitches outside the zone-Average= 30%
  • Z-Swing%  = Swings at pitches inside the zone / pitches inside the zone-Average=65%
  • Swing% = Swings / Pitches-Average=46%
  • O-Contact% = Number of pitches on which contact was made on pitches outside the zone / Swings on pitches outside the zone-Average=66%
  • Z-Contact%  = Number of pitches on which contact was made on pitches inside the zone / Swings on pitches inside the zone-Average=87%
  • Contact% = Number of pitches on which contact was made / Swings-Average=80%
  • Zone% = Pitches in the strike zone / Total pitches-Average=45%
  • F-Strike% = First pitch strikes / PA-Average=59%
  • SwStr% = Swings and misses / Total pitches-Average=9.5%

NOTE: I will not look at  Z-Swing%, Swing%, O-Contact% and Zone%.  I am passing on those because, in my opinion, they don’t necessarily tell much about the pitcher. These numbers are dependent on the hitter, so I’d rather focus on the ones give a clearer picture of what the pitcher controls.

O-Swing%: who got the most swings outside of the zone?

To me, this stat shows us how much a pitcher was able to get the hitter to chase pitches out of the zone. The Cubs’ leaders in this category in 2014 were Pedro Strop (35.9%), Kyle Hendricks (35.4%), and Jake Arrieta (33.4%).

No real surprises here because Strop has that filthy slider and Hendricks works so close to the zone that if his stuff is out of it, it isn’t by far; but he mixes speed and location so well that seeing his name among the leaders was not a surprise. Nor was seeing Arietta, who had awesome stuff for most of the year.

Z-Contact%: who got hit the most in the zone?

My thought with this stat is that it shows you how much contact in the zone a pitcher gave up over the season.  If a pitcher’s percent is high then perhaps they are just a contact pitcher or maybe they just don’t have the velocity to blow it by a hitter.

The pitchers that gave up the most contact in the zone were Chris Rusin (94.8%), Brian Schlitter (94.1%) and Jacob Turner (93.6%).  Those three are more pitch to contact guys, so not a very interesting result, but looking at the pitchers that gave up the least contact in the zone is pretty enlightening.

Zac Rosscup, in a very small sample size gave up contact in the zone 76% of the time.  He was followed by Neil Ramirez (78%) and Pedro Strop (80.2%) which were both above average.

To give some perspective for this stat, Aroldis Chapman by led the relievers with 59.5% Z-Contact, helped by his fastball that touches over 100 MPH consistently (average velocity of his fastball: 100.2 MPH).

Contact%: who gave up the least amount of contact?

This stat will show us whose pitches were hit the least, which can highlight how great a pitcher was at staying away from contact in general. The leaders here were Zac Rosscup (66.1%), Pedro Strop (67.1%), and Neil Ramirez (70.5%) Rosscup may be a bit of a surprise, given his small sample size, but Ramirez and Strop were expected.

Looking at the flip side doesn’t really serve much purpose, because the pitchers that had the most contact–Brian Schlitter (88.2%), Felix Doubront (87.9%), and Jacob Turner (85.7%)–are not exactly strikeout pitchers. All 3 averaged below 6 strikeouts per 9 innings, so these guys are more contact pitchers anyway; their numbers don’t really indicate much to me.

F-Strike%: who threw the most first pitch strikes?

This number shows which pitchers had good control and started the at-bat ahead in the count instead of behind. The leaders (of those who are still Cubs) were Hector Rondon (65.1%), Kyle Hendricks (64.2%), and Justin Grimm (61.3%). Rondon’s ability and willingness to pump first-pitch strikes are good things to have in a closer.

I don’t think the value of starting off an at-bat up 0-1 instead of down 1-0 should be underestimated. You have many more options as a pitcher once you are ahead in the count.

But not all Cubs pitchers were so great at throwing first pitch strikes, namely Wesley Wright (54.6%) and Edwin Jackson (55.6%). Not a shock at all, even though Wright’s numbers weren’t awful in general. We all know just how terrible Jackson was in 2014, but his F-Strike% was not much worse than his career average of 56.3%.

SwStr%: who got the most swings and misses out of their pitches?

Pedro Strop led all Cubs’ pitchers with 15.5% and was tied for 8th among all relievers in baseball (leader was Aroldis Chapman with an absurd 20% swing strikes). Other notable performers were Neil Ramirez (13.3%), Hector Rondon (11.1%), Edwin Jackson (10.8%) and Jake Arrieta (10.2%).

Jackson and Arrieta’s numbers put them in the top 25 for starters, while Strop is the only reliever in the top 30 for the Cubs. That latter fact is perhaps a bit odd, given the relative strength of the Cubs’ pen. But they tended to get hitters out with fewer swings and misses than expected.


There is some value here in the plate discipline metrics for pitchers and they definitely provide a narrative for how a pitcher attacks hitters. Take Pedro Strop for example: he gets a great amount of swinging strikes based on his wipeout slider and out-of-zone swings, which keeps his contact% down to impressive levels.

These numbers can give a hitter an idea of how often a pitcher will throw a first pitch strike, which could lead to a little more aggressive approach. If I was a hitter facing a guy like Strop, I would try to be a little more patient and not swing at “his” pitches. Instead, I’d wait for him to come into the zone or take a walk.

I know, easier said than done. as Strop’s slider looks like a strike for a pretty good chunk of the time until it quickly moves to the outside corner to a right-handed hitter. But this data can at least give a hitter a bit of an idea into what a pitcher does when he is on the mound.

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