**Sean Burroughs** is not content with being one of the best hitting

prospects in all of baseball. He also wants to make his mark in the field of

sabermetrics.

In an interview with David Schoenfield, ESPN.com editor and one of the most

underrated members of the sabermetric revolution, Burroughs gave a novel

answer as to why his long-awaited power had still not arrived (he’s hitting

.352 in Triple-A, but with only five home runs in 236 at-bats.) Referring to

the fact that he bats left-handed but throws right-handed, Burroughs said:

I think it takes a little more time for our power to develop. Our dominant

hand is our right hand, but you need power from both hands when you hit.

Guys like[Ken] Griffeyand[Barry] Bonds, they're

lefty-lefty.

Burroughs also pointed out fellow Futures Game teammate **Adam Dunn**,

also a left-handed hitter but a right-handed thrower, who after hitting

"just" 27 home runs over the past two years, already has hit 30

this season.

Is Burroughs on to something? It’s true that Ken Griffey Jr., a lefty all

the way around, was dropping bombs in the right-field bleachers from the

time he was a teenager. And as Schoenfield writes, "it’s an interesting

concept, especially since Burroughs is often compared to **George
Brett**, a lefty-swinging, righty-throwing third baseman who hit only 20

home runs his first three years in the majors."

The anecdotes piqued our interest, but to test Burroughs’s hypothesis,

anecdotes won’t suffice: we need hard data. Fortunately, we have it.

>From 1920–when home-run power became relevant–through 1993, a total of 318

players have batted 250 or more times in a major-league season at age 21 or

younger. (The same player can be counted more than once; Griffey, for

example, qualifies three times.) Of those 318, only 118 batted exclusively

left-handed. Of *those* 118, 43 throw left-handed (we’ll call them

L-L), and 75 throw right-handed (L-R).

Using Isolated Power (slugging average minus batting average) as a measure

of power, we can divide players into five different cells: less than .080,

.080-.120, .120-.160, .160-.200, and greater than .200. So we can break

these 118 players down this way:

Power Throws L Throws R Total

>.200 2 12 14 .160-.200 10 5 15 .120-.160 13 14 27 .080-.120 14 30 44 <.080 4 14 18

This breakdown defies any obvious trend. On one hand, L-R hitters were

responsible for 12 of the 14 seasons with the most left-handed power before

age 22. The only two L-L hitters with an isolated power above .200 were

Griffey (1991) and **Darryl Strawberry** (1983). Among the L-R hitters,

**Mel Ott** did it three times by himself, **Ted Williams** and

**Eddie Mathews** twice each.

But the rest of the chart indicates that, on average, L-L hitters show more

power than L-R hitters. Twenty-five of the 43 L-L hitters (58%) had an ISP

of .120 or higher. Just 31 of 75 L-R hitters (41%) did the same. Overall,

the 43 L-L hitters under age 22 had an ISP of .136. The 75 L-R hitters had

an ISP of .131, a five-point difference.

Is that significant? Maybe not. Left-handed-throwing infielders (except for

first basemen) are as rare as a funny skit involving Tim Meadows, owing to

the fact that a left-hander would have to pivot awkwardly when throws to

first base. Left-handed-throwing catchers are also essentially non-existent,

although I have yet to hear a good reason why.

So it would stand to reason that L-L hitters would have more power than L-R

hitters anyway, because L-L position players can only play first base or the

outfield. If we look at a control group by comparing L-L hitters vs. L-R

hitters at, say, age 30, we find that L-L hitters have a combined ISP seven

points higher (.145) than L-R hitters (.138). That disparity is two points

higher than the difference between young L-L and L-R hitters, although the

difference between the two numbers is probably not statistically

significant.

To put it in simple terms--in case Allard Baird is reading this Web site for

the first time--among left-handed hitters who make it to the major leagues

at an early age, those who throw left-handed appear no more likely to

exhibit precocious power than those who throw right-handed.

But that isn't exactly the point Burroughs was trying to make. His claim is,

in essence, if two young left-handed hitters both show only modest power,

the one who throws right-handed is more likely to develop power in the

future than the one that throws left-handed.

Let's get back to the chart above. In particular, let's focus just on the

bottom row, which contain the players with the least power:

Power Throws L Throws R Total

<.080 4 14 18

A total of 18 players under the age of 22 have had an isolated power of

under .080. At this point in time, the two groups of hitters, L-L and L-R,

have virtually identical power totals; the L-L hitters have an ISP of .059,

the L-R hitters .061. If we fast-forward and look at how the players perform

five years later, do the L-R hitters hit for more power than the L-L hitters

do?

Only two of the four L-L hitters were still playing regularly five years

later, and they combined for an ISP of .119. Nine of the 14 L-R hitters got

250 PA's, and their combined ISP was .095.

Summarizing these findings in yet another chart:

Bats L, Throws L Bats L, Throws R Power Year 0 ISP Year 5 ISP Year 0 ISP Year 5 ISP Diff

<.080 4 .059 2 .119 14 .061 9 .095 -26

"Difference" refers to how much L-R hitters improved relative to

L-L hitters. In this case, L-R hitters saw their ISP increase by 34 points

five years later, compared to the 60-point increase enjoyed by L-L hitters.

Since the L-R hitters improved by 26 points less than the L-L hitters, they

earn a "Difference" of -26.

That's a very small sample, so let's do the same with each of the rows in

the original chart:

Bats L, Throws L Bats L, Throws R Power Year 0 ISP Year 5 ISP Year 0 ISP Year 5 ISP Diff

>.200 2 .224 2 .301 12 .246 10 .198 -125 .160-.200 10 .185 8 .170 5 .168 5 .160 +7 .120-.160 13 .140 11 .175 14 .136 10 .170 -1 .080-.120 14 .099 10 .111 30 .098 24 .139 +29 <.080 .059 2 .119 14 .061 9 .095 -26

The top row is skewed by the incredibly small sample size of the L-L

hitters, as Griffey is a future Hall of Famer and Strawberry looked like one

for the first seven years of his career. Overall, there does not appear to

be an obvious advantage for either the L-L or the L-R hitters. However, that

29-point advantage enjoyed by the L-R hitters in the next-to-bottom row

looks intriguing, especially since the sample size is the largest of all the

rows.

Now we'll look at the same chart, but change the criteria to look at

slightly older hitters, guys who were 22 or 23 years old in their original

season. Those players are still young enough to develop power as they age,

and looking at older players provides us a much larger sample size to

examine the issue. In addition, we'll eliminate the top two rows entirely,

because those players have already shown they can hit for power, so they

really aren't germane to the question at hand.

Bats L, Throws L Bats L, Throws R Power Year 0 ISP Year 5 ISP Year 0 ISP Year 5 ISP Diff

.120-.160 45 .141 37 .154 6 .137 45 .155 +5 .080-.120 39 .098 22 .113 60 .103 38 .120 +2 <.080 16 .060 10 .108 39 .062 22 .107 -3

The increased sample sizes have helped to smooth out the data, and what the

data shows is that there's no real difference between the two groups.

We could tweak the study in many other ways, lowering the PA requirement,

looking three years ahead instead of five years, whatever. I'll agree to

spare you the tedium of looking at more lists if you'll agree to trust me

when I tell you that none of them show any significant difference between

the two groups.

There's one other factor we should consider, though. We've already

established that the lack of L-L middle infielders and catchers means that,

overall, L-L hitters have more power than L-R hitters. It has also been

shown (by Bill James, in the *1987 Baseball Abstract*) that, presumably

owing to the physical demands of their positions, second basemen and

catchers tend to develop less than players at other positions. Since there

are no L-L hitters at either position, is it possible that if we match

players from each group with players at the same position, that a difference

between the two groups will finally emerge?

Only one way to find out. The following chart consists only of players who

were 22 and younger, and who were primarily outfielders during their

original season (defined as 50 or more games played in the outfield):

Bats L, Throws L Bats L, Throws R Power Year 0 ISP Year 5 ISP Year 0 ISP Year 5 ISP Diff.120-.160 18 .144 15 .162 23 .139 15 .167 +10 .080-.120 21 .100 19 .121 23 .104 19 .145 +20 <.080 7 .068 4 .115 12 .066 9 .107 -6

There might--stress might--some evidence here to back up Burroughs' claim.

The L-R hitters do not fare well in the bottom row, but the sample size is

by far the smallest of the three groups, and the advantages shown by the L-R

hitters in the other two groups are fairly sizable. If we combine all three

rows together, giving us a total sample size of 38 L-L and 43 L-R seasons in

the follow-up group, L-R hitters have an overall advantage of 11 points of

isolated power.

I imagine there's a way to determine whether a difference this large, in a

sample this large, is statistically significant or not. Unfortunately, I

neglected to take that particular class in college, so I'm forced to use

inference to determine whether the difference is real or not. And there is

at least one additional reason to believe that the advantage enjoyed by

young L-R hitters is real: the advantage appears to fade as the players age.

The 11-point edge for L-R hitters includes all outfielders 22 and under. If

we look solely at outfielders 21 and under, the advantage is actually 13

points; for 22-year-olds, it slips to seven points. Among 23-year-old

outfielders, there doesn't appear to be any advantage at all; in fact, L-L

hitters actually fare two points better than L-R hitters.

Nevertheless, I'm not willing to hang my hat on Burroughs's statement just

yet. To reach a firm conclusion would require a study of hundreds of

hitters, and there simply isn't enough data available, at least not in the

major leagues. A study including minor-league players would feature enough

young players, but trying to compare hitters at various minor-league levels

might only muddy an issue that is murky enough as it is.

And even if the L-R advantage is real in statistical terms, is it

significant in baseball terms? Suppose we use the most generous evidence in

the study and project a young L-R player like Burroughs (who is still just

20 years old) to pick up an extra 13 points of slugging average relative to

his L-L counterpart, say someone like **Josh Hamilton**, over the course

of the next five years. Thirteen points of slugging average comes out to

about seven total bases over the course of a season, the equivalent of

converting three singles into a double and a pair of home runs. That's not

trivial, but neither is it large enough to change the outlook of a young

player one way or the other.

Or to put it another way: if Burroughs develops the 25-homer power that

everyone expects from him, there will be no reason to think he wouldn't have

developed his home run swing had he thrown with his left hand.

*Rany Jazayerli is an author of Baseball Prospectus. You can contact him by
clicking here.*

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