Another way of viewing the historic performance of Bryce Harper

Bryce Harper had a historic season in 2015, and examining his damage rate offers further proof of just how amazing it was.

Bryce Harper began last season with a goal: Do more damage by swinging less often.

“We talked about being smarter about your swings,” said Scott Boras, the agent for the Nationals' star outfielder. “I call it keeping power in reserve. We talked about how Barry Bonds did it, to preserve your swings.”

The idea is to use the swing judiciously—to use it not to just hit the baseball, but to do damage with it. The result? In 2015, Harper swung at a career-low percentage of pitches (45.2), hit a career high in home runs (42, almost double his previous high of 22) and won the National League MVP award.

Harper’s efficiency also may have been influenced by injuries to his Washington teammates, especially Ryan Zimmerman. Pitchers had little reason to challenge Harper because of his power and the lack of a steady threat behind him. Zimmerman started the most games behind Harper, but that was less than half the season (77), followed by Jayson Werth and Wilson Ramos (20 each), Yunel Escobar (18), Clint Robinson (8), Anthony Rendon (4) and Ian Desmond and Tyler Moore (one each).

“The health of Ryan Zimmerman is a huge key for the team,” Boras said, “because he is a great, great hitter. He is so strong. He can be a 30-home run hitter. Bryce didn’t have him for most of last season.”

Harper drew 124 walks—more than double his previous career high—and led the league in runs. According to baseball-reference.com, Harper is the only player in the last 100 years to twice in the same season score four runs in a game without a hit. It’s possible that Harper could post an even more monstrous season if Washington’s everyday players remain healthier than they did last year.

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What’s known is that Harper turned an important corner last year with his selectively at the plate. He may still only be 23 years old, but he has the wisdom of a more senior player, thanks to the 2,143 plate appearances he already has in the bank—making him just the 16th player since 1901 with so many reps at such a young age—as well as an extremely high baseball IQ.

Harper’s adjustment in turning patience into power got me thinking about how to measure “power in reserve.” So I decided to explore the relationship between how often Harper swings and how often those swings result in a home run. (I removed all intentional balls from these and other calculations below.) Here you can see the stunning improvement he made last year:

Year	Pitches	Swings	Swing%	HR	Damage Rate
2012	2,307	1,163	50.4	22	1.89
2013	1,944	947	48.7	20	2.11
2014	1,523	783	51.4	13	1.66
2015	2,621	1,185	45.2	42	3.54

Damage Rate is the percentage of swings that result in a home run. Harper doubled his damage rate last year. The major league average last season was 1.49, meaning Harper does home run damage with his swings at more than twice the rate of an average hitter.

That Damage Rate led to my next question: How does it compare to other sluggers? I considered the Damage Rate of all players who hit at least 20 home runs last year. Harper didn’t crack the top five. The data turned up two especially interesting nuggets: the guy at the top of the list is an absolute freak as a slugger—nobody in baseball is close to him—and the old first baseman for the New York Yankees isn’t close to being done yet.

1. Giancarlo Stanton: 4.99
2. Mark Teixeira: 3.99
3. Jose Bautista: 3.73
4. Mike Trout: 3.68
5. Edwin Encarnacion: 3.59
5. Chris Davis: 3.59
7. Bryce Harper: 3.54
8. Albert Pujols: 3.51
9. Nelson Cruz: 3.49
10. Nolan Arenado: 3.41
11. David Ortiz: 3.35
12. Carlos Gonzalez: 3.34
13. Josh Donaldson: 3.18
14. Khris Davis: 3.15
15. Pedro Alvarez: 3.05

We already have metrics that show the 26-year-old Stanton hits the ball harder than everyone else; now there is evidence he is in a class by himself when it comes to how often the ball leaves the park when he swings.

Things got really interesting when, just for fun, I lowered the qualifier to just five home runs. Of course, now we’re introducing small sample sizes, but I found most of the names fascinating nonetheless—including that three of the top seven Damage Rates belonged to the Tampa Bay Rays, the team that ranked next to last in the AL in runs scored.

1. Jarrett Parker: 5.71
2. Giancarlo Stanton: 4.99
3. Curt Casali: 4.90
4. Franklin Gutierrez: 4.21
5. Mark Teixeira: 3.99
6. Mikie Mahtook: 3.98
7. J.P. Arencibia: 3.85
8. Adam Duvall: 3.76
9. Jose Bautista: 3.73
10: Mike Trout: 3.68

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Now that’s an eclectic list. Jarrett Parker? Until last September, if he was known at all it was for getting called up to the San Francisco Giants in August of 2014 and sent back the next day without getting into a game—a whiff, not a cup, of coffee that earned him a World Series ring. He didn’t make it back to the bigs until the following June, when he went 1 for 9 and was demoted again. Back in San Francisco again for 17 games in September, Parker hit a ridiculous .400/.467/.900. Overall he hit six home runs in just 105 swings. Parker, 27, is competing for a fifth outfielder spot this spring.

Just as unlikely near the top of the list is another rather anonymous 27-year-old, Rays catcher Curt Casali. He hit .238 in 38 games in 2015 but smashed 10 home runs with 204 swings. He was joined among the top seven by teammates Mikie Mahtook and J.P. Arencibia.

By the way, Giants pitcher Madison Bumgarner, with his five home runs in 165 swings, clocked in at a 3.03 Damage Rate, which is a couple of ticks better than the 3.01 mark of Yankees designated hitter Alex Rodriguez.

Next I wanted to take a look at Harper with a wider lens: How does his Damage Rate compare to those of Mark McGwire and Sammy Sosa during the Great Home Run Race of 1998?

Player, Year	Damage Rate	MLB Damage Rate
Harper, 2015	3.54	1.49
McGwire, 1998	6.67	1.60
Sosa, 1998	4.99	1.60

That’s just another example of why the Steroid Era is so disconnected from the entirety of baseball history.

But wait, you haven’t seen anything yet when it comes to chemically enhanced numbers to ridiculous proportions. Boras mentioned Bonds as the model of power in reserve. Bonds established a reputation for his uncanny ability to watch pitch after pitch go by and still be ready to hammer the rare one that he liked.

So now let’s match Harper, in his age-22 season, against Bonds from ages 35 through 39, which—holy cream and holy clear, Batman—happened to be five of his six greatest home run hitting seasons. Remember, intentional balls are not counted (Bonds saw 480 of them one year.)

Player, year	Damage Rate	MLB Damage Rate
Harper, 2015	3.54	1.49
Bonds, 2000	5.43	1.77
Bonds, 2001	8.38	1.71
Bonds, 2002	6.18	1.59
Bonds, 2003	6.12	1.63
Bonds, 2004	6.77	1.69

That's just silly. In 2001, Bonds swung at just 34.4% of the pitches he saw. Only one other hitter swung the bat less often that year: Frank Menechino. Bonds and Menechino are now the hitting coaches for the Miami Marlins.

Bonds hit 73 home runs swinging the bat only 871 times (439 times fewer than 2015 major league home run leader Chris Davis). That’s roughly one home run for every 12 times he swung the bat. We’ve seen guys who can’t do that in home run derby off a BP pitcher throwing 55 mph. (Davis averaged 28 swings per homer to get his 47.)

How silly was Bonds’s season? If you gave Bonds as many swings in 2001 as Davis had last year, assuming Bonds’s same damage rate, he would have hit 110 home runs.

The Bonds comparison to Harper, or anyone, falls apart because of the performance-enhancing drugs Bonds is alleged to have used. Bonds had banked more than 8,500 plate appearances and was 35 years old by the time he went off on the greatest home run binge of his life; he combined the physical gifts of a false youth with the wisdom and experience of being an elder.

The only true comps for what Harper did last year—the freakish combination of power and patience with true youth—are few, and all of them are long dead. Harper joined Hall of Famers Mel Ott (1929) and Eddie Mathews ('54) as the only players to reach the thresholds of 40 homers and 100 walks in the same year before they turned 23. Both Ott and Mathews came back the next year with nearly identical huge seasons. Both went on to the 500 Home Run Club with nearly identical numbers; Mathews’s 512 homers were one more than Ott hit.

“Power in reserve” is next-level stuff typically acquired by veterans, the grandmasters of hitting. There have been 120 seasons in which a player hit 40 homers and walked 100 times; 89% of them were by men 25 and older. So there is a word for what Harper has learned already: historic.

The kid who left high school at 16, hit .443 in junior college at 17 and had more total bases than any teenager in major league history at 19 is now the only man alive to show such an elite combination of power and patience at 22. We are looking at a rare baseball prodigy.