2013's Ks and GBs for starting pitchers: The 'Winter Soldier'

Sometimes, an off-handed Tweet sends you thinking.

Another pitcher more interesting moving forward: Dallas Keuchel. Adding the slider made him a K/GB guy, and those are kind of neat

— Brandon Warne (@Brandon_Warne) January 1, 2014

Though I shouldn't make a habit of calling anyone a KGB guy, probably

— Brandon Warne (@Brandon_Warne) January 1, 2014

Thanks, Brandon!

First things first, I like calling a guy who gets strikeouts and ground balls a KGB guy because it's mildly amusing. If you had an elite K/GB guy, I guess you could call him Spetznaz, but since I'm also a comic book nerd, I'd think you could call an elite K/GB guy The Winter Soldier. Y'know, after a character in Captain America comics -- and in a movie this coming summer.

But, as usual, I digress.

Back on baseball, I love ground ball pitchers, and the more I can read and write about them, the happier I am. It's what keeps me fascinated with guys like Trevor Cahill and Brad Ziegler, despite the advancements in DIPS theory over the years. And guys who can complement ground ball ability with good strikeout numbers are great assets, and usually wind up being very strong parts of a pitching staff.

Given that K% and GB% are two skills with a relatively good year-to-year correlation -- thanks to Steve Staude's correlations tool at FanGraphs -- it's worth finding out which pitchers can do these two things well. Ground ball percentage has a base correlation of 0.752, and strikeout rate has a base correlation of 0.702, so from season to season, these are skills that tend to be more predictive than not.

So that left me with the desire to find out which pitchers in 2013 were the best at both of those things. With that information, we might be able to identify a couple of guys who could be better than expected next season. So why not develop a bit of a toy stat to measure a pitcher's combined ability to strike out batters while getting ground ball outs?

Creating a KGB Score

What I care about are ground balls and strikeouts, and for my initial population, I'll pull data from qualified starting pitchers. To explore those two areas of a pitcher's game, my best initial tools are probably GB% (percentage of batted balls that are ground balls) and K% (percentage of batters struck out). We'll start there.

Next, I found the league-average numbers for starting pitchers. I want the guys I'm going to look at to be better than average at both things, so I'll need to judge against those league-average marks. League-average GB% for starters was 44.6% in 2013, while league-average K% was 18.9%.

Now I'd like to put those two marks on a level playing field. As such, I'll find GB%+ and K%+, two stats that measure how much better the pitcher's peripheral was as compared to the league average. Anything over 100 should be above league-average. To find them, I use the formula (value x 100) / league average.

To create my final KGB score, I just take those GB%+ and K%+ numbers, add them together, and subtract 200 from the total number. This gives me just the percentage above league-average for each stat, combined on equal footing.

With all that said, let's look at the 26 qualified starters who were worthy of a KGB score in 2013. The best of them all earns the title "Winter Soldier" for the season.

Num	Player Name	Team	IP	GB%	GB%+	K%	K%+	KGB
1	A.J. Burnett	PIT	191.00	56.5	126.7	26.1	138.1	64.8
2	Justin Masterson	CLE	193.00	58.0	130.0	24.3	128.6	58.6
3	Felix Hernandez	SEA	204.33	51.4	115.2	26.3	139.2	54.4
4	Stephen Strasburg	WAS	183.00	51.5	115.5	26.1	138.1	53.6
5	Matt Harvey	NYM	178.33	47.7	107.0	27.7	146.6	53.6
6	Jose Fernandez	MIA	172.66	45.1	101.1	27.5	145.5	46.6
7	Anibal Sanchez	DET	182.00	45.4	101.8	27.1	143.4	45.2
8	Chris Sale	CHW	214.33	46.6	104.5	26.1	138.1	42.6
9	Clayton Kershaw	LAD	236.00	46.0	103.1	25.6	135.5	38.6
10	Madison Bumgarner	SFG	201.33	46.8	104.9	24.8	131.2	36.1
11	Jeff Samardzija	CHC	213.66	48.2	108.1	23.4	123.8	31.9
12	Adam Wainwright	STL	241.66	49.1	110.1	22.9	121.2	31.3
13	Homer Bailey	CIN	209.00	46.1	103.4	23.4	123.8	27.2
14	Rick Porcello	DET	177.00	55.3	124.0	19.3	102.1	26.1
15	Tim Lincecum	SFG	197.66	45.3	101.6	23.0	121.7	23.3
16	Hisashi Iwakuma	SEA	219.66	48.7	109.2	21.4	113.2	22.4
17	Hyun-Jin Ryu	LAD	192.00	50.6	113.5	19.7	104.2	17.7
18	John Lackey	BOS	189.33	46.8	104.9	20.7	109.5	14.4
19	Patrick Corbin	ARI	208.33	46.7	104.7	20.7	109.5	14.2
20	Mat Latos	CIN	210.66	45.1	101.1	21.2	112.2	13.3
21	Zack Greinke	LAD	177.66	45.6	102.2	20.6	109.0	11.2
22	David Price	TBR	186.66	44.9	100.7	20.4	107.9	8.6
23	Felix Doubront	BOS	162.33	45.6	102.3	19.7	104.2	6.5
24	Jon Lester	BOS	213.33	45.0	100.9	19.6	103.7	4.6
25	Kris Medlen	ATL	197.00	45.3	101.6	19.2	101.6	3.2
26	C.C. Sabathia	NYY	211.00	44.7	100.2	19.3	102.1	2.3

Cool. The guy who I've deemed as the best at both getting strikeouts and ground balls last season ... is thinking about retiring. 2013's Winter Soldier was A.J. Burnett, who was 27% better than the league-average starter in getting ground balls, while pairing that with being about 38% better than league-average at getting punchouts. In fact, Burnett was second in baseball among qualified starters at getting groundballs, with only KGB rater No. 2 Justin Masterson placing above him on that particular leaderboard.

It's interesting to see that Burnett and Masterson are the one-two punch atop my KGB leaderboard, but the rest of the top 10 is basically a who's who of dominant aces. Felix, Strasburg, Harvey, Fernandez, Sanchez, Sale, Kershaw and Bumgarner. That's hardly chopped liver, and some of the scariest starters in the bigs. In fact, looking at the entire list, you'll see primarily very, very good pitchers on your KGB score list. Only a few outliers, guys like Yu Darvish and Justin Verlander, who don't get above-average GB% numbers, comprise baseball's elite starters but fall off this list.

Of course, there are a few real surprises on the list too -- first among them is probably Rick Porcello of the Tigers, who rides his asinine ground ball rate to the 14th spot on the list. Porcello barely makes the cut on strikeouts, but he does, and he saw that K% shoot up during a breakout 2013. If he can keep up league-average whiffs to pair with his heavy fastball, he could be a force going forward.

A few falling stars also show on the list, with Tim Lincecum sitting fairly pretty at No. 15 and C.C. Sabathia riding the caboose at No. 26. Both of these players were flawed last season, as they appeared unable to strand runners on base and their ERAs suffered. Both saw their strikeouts diminish from their previous ace levels, and perhaps each needs to find a way to perform with diminshed stuff in order to be effective. Perhaps upping the GB% could help?

Last, with apologies to Brandon, Dallas Keuchel doesn't quite make my KGB score list, even if I were to lower the IP restriction to 150 IP last season. While Keuchel did up his strikeout game, his rate of 18.0% doesn't put him above average for starters, and that doesn't even take into account his relief appearances.

At the same time, he could be a player to watch going into next season, as pitchers who manage above-average numbers in both GB% and K% tend to be the better ones in the league, at least when it comes to starters.

. . .

All statistics courtesy of FanGraphs and Baseball-Reference.

Bryan Grosnick is the Managing Editor of Beyond the Box Score. You can follow him on Twitter at @bgrosnick.