In Defense of Striking Out: Ideal Strikeout Rates for Hitters

Strikeout rates have climbed since 2006, while league wOBA has dropped.  Responses to ballooning strikeout rates have been mixed. One response is to trade one of your best hitters, while another is to lead the MLB in home runs. Some clubs are more averse to strikeouts than others.

It’s no secret that Diamondbacks GM Kevin Towers hates strikeouts. Since taking over in 2010, Towers has discarded every Diamondbacks player who struck out 100 times or more from the 2010 club that set the major-league record for strikeouts in a season by striking out 24.7% of the time. His 2013 squad’s 18.5% strikeout rate is 10th-lowest in the majors. However, the decreased strikeout rate has not resulted in increased offense. The 2010 D-Backs scored 4.40 runs per game, posting a .325 wOBA and 93 wRC+, a shade better than that of the more contact-driven 2013 Diamondbacks who currently average 4.17 runs per game with a .313 wOBA and 92 wRC+. While the 2010 team had the 4th-best walk rate at 9.5%, the 2013 Diamondbacks are just 13th at 8.1%. Though the 2010 Diamondbacks struck out more, they also walked more, and made more quality contact, as shown by a .312 BABIP% and .166 ISO which were 2nd and 4th in the majors, respectively. The 2013 team has a .301 BABIP% and .135 ISO, good for 10th and 23rd in the majors. A look at the plate discipline numbers shows that the 2013 Diamondbacks swing at more pitches out of the strike zone and make more contact on those swings than the 2010 team.

2010	O-Swing%	Z-Swing%	Swing%	O-Contact%	Z-Contact%	Contact%	Zone%	F-Strike%	SwStr%
Diamondbacks	27.6%	64.7%	44.6%	57.9%	84.2%	75.4%	45.8%	58.5%	10.6%

2013	O-Swing%	Z-Swing%	Swing%	O-Contact%	Z-Contact%	Contact%	Zone%	F-Strike%	SwStr%
Diamondbacks	31.4%	64.8%	46.4%	68.6%	87.8%	80.6%	44.9%	59.9%	8.7%

If a hitter can cut his strikeout rate while maintaining his walk rate and power production, that is special. However, there is usually a tradeoff between power/walks and contact. After all, not everyone can be vintage Albert Pujols. To dig deeper into the balance between power and contact, I separated MLB hitters by strikeout percentage into five groups, with 30 hitters per group. I limited the study to qualified hitters, to eliminate the presence of pitchers and small sample size hitters. Not surprisingly, the first group was the clear leader in home run rate.

MLB	K%	BB%	HR%	wOBA	BABIP%	WAR	Total PA
	19.7	7.9	2.6	0.313	0.296
Group 1	K%	BB%	HR%	wOBA	BABIP%	WAR	Total PA
	27.2	8.7	4.4	0.336	0.305	61.7	13008
Group 2	K%	BB%	HR%	wOBA	BABIP%	WAR	Total PA
	20.7	8.6	2.5	0.337	0.323	65.9	12962
Group 3	K%	BB%	HR%	wOBA	BABIP%	WAR	Total PA
	17.1	8.1	3.0	0.342	0.313	68.9	13510
Group 4	K%	BB%	HR%	wOBA	BABIP%	WAR	Total PA
	14.3	8.5	2.4	0.342	0.313	71.5	13895
Group 5	K%	BB%	HR%	wOBA	BABIP%	WAR	Total PA
	10.4	7.0	2.1	0.317	0.284	51.9	13187

I included WAR even though it includes defensive and baserunning values because I thought that the contact-heavy hitters in group 5 might make up for their offensive deficiencies by being better defenders or baserunners. However, the total WAR for each group tracked offensive production for the most part. The first four groups are very close together with regards to wOBA. As I expected, the most strikeout-heavy group owned the highest walk and home run rates. Group 2 made up for its lower home run rate with a higher BABIP%. The rates of doubles were very close in all groups, ranging from 4.5% in group 5 to 5.2% in group 3. Group 5 had the lowest homerun and walk rates. Despite group 5’s ability to put the ball in play, the contact generated was of a lesser quality due to higher contact rates on pitches out of the zone. With the exception of Edwin Encarnacion, Adrian Beltre, and Buster Posey, none of the hitters in group 5 had more than 20 weighted runs above average (wRAA). The group average was 0.9 wRAA. Though group 5 had the lowest WAR of any group by a wide margin, they had the 3rd most plate appearances.

As the above table shows, there is not a significant negative connection between higher strikeout rates and offensive production. In fact, the most contact-heavy hitters are far less productive offensively than their more strikeout-prone counterparts. Of course, the plate approach of Chris Davis would not work for Marco Scutaro and vice versa. The idea of an ideal groundball rate for individual hitters has been posited. I would suggest that there is also an ideal strikeout rate for individual hitters. The following is a list of five hitters who I believe would benefit from a more or less contact-friendly approach.

Matt Holliday has trimmed his strikeout rate from 19.2% in 2012 to 14.4% this year. However, he has also trimmed his wRC+ from 141 to 137. His BABIP% is down from .337 to .312, but this is likely due to a less formidable batted ball profile, as his xBABIP% has dropped from .328 to .304. His Line Drive/Infield Fly ratio is down from 89/11 to 58/16. Furthermore, his home runs on contact has dropped from 5.7% to 4.8% and his overall homerun rate has dropped from 4.9% to 3.5%. His flyball distance has decreased from 305.15 to 294.66. A look at the PITCHf/x data shows that Holliday is swinging more and making more contact on those swings. His Swing% has jumped from 47.2 to 49.9 and his Contact% has gone from 78.5 to 81.8. His O-contact% has gone from 65.0 to 66.1 and his Z-contact from 86.1 to 89.0. While Holliday is striking out less while walking at the same rate, his swings have been noticeably less aggressive, and his overall offensive production is down.

Mike Moustakas has reduced his strikeouts even more than Matt Holliday, going from 20.2% in 2012 to 13.6% in 2012 while essentially maintaining his walk rate. However, his offensive production is down significantly, from 90 wRC+ to 79 wRC+. His home run rate has dropped from 3.3% to 2.6%, and his home runs on contact is a paltry 3.3% compared to 4.5% in 2012. His fly ball distance has dropped to 279.2 to 274.6. Moustakas’ increased contact rate has come largely from swings on balls outside of the zone, as he has seen as increase in O-Contact% from 63.7 to 74.3. During GM Dayton Moore’s tenure, the Royals have had an emphasis on putting the ball into play. Their 16.4 K% since 2007 is the lowest in the league over that time frame. However, they have only a 92 wRC+ over that span, good for 21st in the league and their BB% of 7.0 is dead last. While the Royals’ emphasis on contact appears to have helped Eric Hosmer, its application to Moustakas has had a negative impact on his production.

Adrian Gonzalez has undergone a significant change since being traded from the Padres. While playing in the spacious Petco Park Gonzalez posted home run rates between 3.8-5.9% and walk rates of 8.2-17.5%. His wRC+ numbers ranged from 123 to 156. His home run rate dipped to 3.8% in his first year at Fenway, his lowest since his first full season, but a still solid walk rate of 10.3% and a .380 BABIP% led him to an excellent 154 wRC+. Since then, his ability to draw walks and hit for power have plummeted. From 2012 to the present, Gonzalez has a 2.9 HR% and a 6.7 BB%. While Gonzalez has posted his three best contact rates since 2011, his O-Contact% has been between 70.1 and 75.9, well above his career rate of 67.1. Though Gonzalez has slightly improved his power production from 2012, his 126 wRC+ remains a far cry from his peak years. In Gonzalez’ best years, he had strikeout rates in the 17-20% range. He can still be a productive player, but the make-contact approach has taken away much of his power and walks.

Asdrubal Cabrera is posting career high strikeout and fly-ball rates in 2013. Unfortunately for him, this approach has not led to an increased power output, as his home runs on contact, average fly ball distance, and ISO are virtually unchanged from 2012. The 22.0% strikeout rate has conspired to cut his wRC+ from 113 to 91. In an effort to hit for more power, Cabrera’s contact rate has gone from 84.0% to 78.6%, a career-low figure, and his walk rate has dropped from 8.4% to 5.8%, also a career low. Though Cabrera’s BABIP%  has dropped from .303 to .286, his xBABIP% is up from .319 to .334, suggesting that he can be productive when he puts the ball in play. Not yet 28, it is time for the Indians shortstop to go back to the plate approach that made him a productive hitter in 2009-12, controlling the strike zone with a more level swing. In picture form, here is a swing from 2011 when Cabrera had a K% of 17.8 and a 119 wRC+.

 Yoenis Cespedes has improved his home runs on contact from 5.9% in 2012 to 6.4% in 2013. However, because of the jump in his strikeout rate from 18.9% to 23.9% his overall home-run rate remains at 4.3% and his ISO is basically the same. His wRC+ is only 96, compared to 136 in his debut season. Cespedes is hitting more fly balls at 47.7% compared to 39.9%, and their average distance is the same, but those fly balls have come at the expense of line drives and ground balls, which has caused his xBABIP% to sink from .305 to .279 and his actual BABIP% to go from .326 to .255. Because Cespedes is relatively new to the league, I wanted to see if pitchers are attacking him differently. However, Cespedes has been pitched to in largely the same fashion as 2012, but with slightly more fastballs and less changeups. Cespedes has been less able to hit those fastballs, as he is only 0.37 runs above average per 100 fastballs, compared to 1.71 last year. Cespedes has been seeing slightly more pitches out of the zone, as his Zone% has decreased from 46.2% to 45.1%, but his O-Zone Swing% is mostly the same. For the most part, Cespedes has been getting beat in the strike zone, as his Z-Contact% down from 84.2% to 81.0%. Because Cespedes’ raw power and athleticism are so impressive, there is a temptation to be overaggressive at the plate. He will likely always be an aggressive hitter, but if he can cut his strikeout rate to his 2012 level, it will be worth the decrease in home runs on contact.

Unlike many people, I do not think that strikeouts are inherently bad. For some hitters, the increased strikeouts are the cost of home runs and walks. Other hitters would be well served to put more balls in play while suffering a loss of power. However, start implementing a one-size fits all approach of strikeout avoidance and you’ll end up like the Royals.