Last week, we looked at how we can interpret groundball averages and what they tell us about the defensive overshift. Now, we'd like to examine some of the more interesting points in our dataset. Of all left-handed batters with at least 200 grounders since 2002, who had the most success with the worm-burner?

The chart is sorted by groundball average, which for lefties averages out around .225-.230. It is followed by expected groundball average based on pull-to-opposite-field-groundball ratio, speed score, percentage of groundballs to center field, homers per ball in air, and bunts per plate appearance.

Fred Lewis is quite the ballplayer. He has one of the top speed scores in our sample, and according to Pizza Cutter’s speed scores, he was one of the top 35 fastest players in the game last year. But he makes the most of his abilities. Not only can he leg out grounders, but by advanced metrics, he’s an above average left-fielder and baserunner. He stretches hits into triples and is willing to draw a walk to boot. Just wanted to make that observation before we get to...

Land of the Rising GBAVG

Ever notice that all four current Japanese Major League regular position players bat left handed? Though Ichiro Suzuki, Akinori Iwamura, Hideki Matsui, and Kosuke Fukudome all slugged at least 95 points higher in Japan than they have in America, there is one department in which they presumably haven’t suffered since coming overseas. All four players have a strong propensity to reach base via the groundball. Iwamura, Ichiro, and Fukudome all show up on the top 10 list, while Matsui checks in with a .246 groundball average, impressive considering his affliction going the other way. Calculating the difference between their groundball average, and their “expected” groundball average, all four come up in the 20 most “lucky” hitters. However, we wouldn’t attribute their success to luck at all. Ichiro is famous for his unique swing, in which he opens his bottom half and basically is halfway down the line by the time he makes contact. Could this be a method that is taught in Japan? If so, it would probably give someone a much better chance than other lefties of reaching base on grounders. Looking at cherry-picked at-bats, we can say that Iwamura, Matsui, and Fukudome all at times follow similar approaches.

We can estimate that without this skill, over the observed years, Iwamura would have a .260 batting average instead of .280, while Ichiro would be a .310 hitter instead of .330, Matsui .285 instead of .295 and Fukudome .245 instead of .255. This is a remarkable ability. It would be difficult to quantify, but perhaps teams can start timing how long it takes for a batter to get to first following contact. While Matsui has yet to bunt in his career, Ichiro, Iwamura, and Fukudome all get hits on over half their bunt attempts. Perhaps in Japan they emphasize getting down the line, and perhaps in America they should start looking into that. (Cough, Manny, Cough.)

The players we've looked at so far all make the most of their speed and groundball opportunities. But who doesn't? Without further ado...

The Willie Mays Hayes All-Stars

“You gotta stop swingin’ for the fences though, Hayes. All you’re gonna do is give yourself a hernia. With your speed you should be hittin’ the ball on the ground, leggin’ ‘em out. Every time I see you hit one in the air, you owe me twenty pushups.” --Lou Brown (Major League)

Disclaimer: It would be quite a rare instance to find a player who would actually benefit from hitting more grounders than flyballs. We suggest referencing The Hardball Times Baseball Annuals to find specific run values for players' different batted ball types. These are simply players who do a great job reaching base on grounders but fail to do so often.

Chone Figgins: From the right side, it’s acceptable that he doesn't hit many groundballs. Batting righty, he has hit only .230 on grounders over the last six years, while he is also more likely go earn a hit when he gets underneath the ball from that side of the plate than when he does so from the left side. Meanwhile, Figgins not only bats a robust .290 on grounders from his left side but is also very successful bunter. So when Figgins swings for the fences with his career .100 ISO from the left-handed box, know he might be better off legging out grounders.

Iwamura: Aki may have been a 30 homerun a year hitter in Japan, but not anymore, as he is twice as likely to have his groundballs go for hits than his fly balls. His homerun per flyball ratio has decreased to 3.7% this year, and the average true distance of his homeruns has gone down nearly ten feet as well, according to hit tracker. But he’s still a monster when he puts the ball into the turf, except he does so at only a league average rate.

Mark Bellhorn is the final player on this list, and oddly, another 2b/3b combo. Bellhorn may never get another cup of coffee, so it is likely too late for him to change his approach. But it warrants mentioning that he's always been underappreciated in his career due to his strong secondary skills, and he's been able to compile a nice groundball average despite a low groundball percentage.

Curtis Granderson and Brian Roberts could also be on this list, except that they're able to hit however they please and remain successful. Both players hit balls in the air almost twice as often as on the ground, though they hold solid career GB averages in the .265-.275 range. But Roberts consistently hits for decent power, and while Granderson has been excellent at reaching base on ground balls all four full years of his Major League career, he has done a good job of decreasing his groundball percentage as his power has increased--perhaps a conscious decision. Take a look at these graphs:

Follow the green lines. As his groundball percentage decreases, his production as measured by wOBA has increased. Though he hit .305 on grounders this year, putting the ball on the ground actually hurt his overall line it appears. He's a better hitter when hitting fewer groundballs, or he hits fewer groundballs to be a better hitter. Either way, he's done a great job improving at the plate

Taking a quick look at righties who weren’t in our dataset: Over the last three years, the only player to have popped up 20% of his fly balls was Eric Byrnes, with a 25.2 infield flyball percentage. As one of the faster players in the game, he could probably use to hit a few more grounders, and he has hit .296 on them since 2002. Carlos Gomez has a similar batted ball profile to that of Byrnes, except without the same type of pop, so he'll either want to develop some muscle or stop racking up 140 strikeouts with a .360 SLG when he might be better off at times pounding the ball into the ground and beating out the throw.

On the reverse end, grounders have been death to Mark Sweeney, Casey Kotchman, and Russ Adams, to the tune of a sub-.200 average, yet they still hit more balls on the ground than in the air.

That's it for our findings on batted ball data. Big thanks to FanGraphs and BillJamesOnline for making this type of data available. And we'd also like to express our deepest gratitude to Rich Lederer for hosting our research.

Leanne Brotsky, David Estabrook, Jeremy Greenhouse, Kimberly Miner, and Steven Smith assisted in writing this article. We would also like to thank Evan Chiachiaro and Dan Rathman, and Anthony Doina who participated in Baseball Analysis at Tufts’ research committee. Any questions can be directed to TuftsBAT@gmail.com.