- FanGraphs Baseball - http://www.fangraphs.com/blogs -

Grabbing the Knob of the Bat: A Bad Idea?

Yoenis Cespedes is on his rehab assignment and nearing a return this weekend. When he returns, something will be different about him. Beyond the fact that he might play left field — he’s played there at least once while in the minor leagues — the careful observer might notice something different about his swing. The Athletics have asked him to stop holding the knob of the bat. From Susan Slusser:

There is thought that holding the knob in the palm might have contributed to the strained hand muscle that put him on the DL this month.

Sluggers have used this grip since the days of Babe Ruth if you listen to the stories. Has the practice been contributing to injury all this time?

Trying to start with the players that use that grip and then investigate their instance of injury seems like folly. There is no system that records bat grip now, and combing through the names one-by-one just points out the impossibility of even finding even an anecdotal answer.

Twitter-sourcing gets you some names. Pablo Sandoval is the first player that comes to mind — he’s gripped the knob his whole career and now he has no hamate bones. David Ortiz has had some famous wrist problems. Mark McGwire held the bat as far down as he could, and he had some wrist injuries. Jason Heyward is a knob-grabber and has had some thumb problems in his young career. Juan Uribe‘s career is littered with wrist problems. Brandon Phillips has been fairly healthy, but when he has missed days, it’s often been to hand and wrist situations — about five days a year for the past five years at least.

But Miguel Cabrera grips the bat at the end and has been remarkably healthy over his career, and even teammate Magglio Ordonez can’t blame all those leg injuries on his grip. Ryan Howard also uses the grip, and he’s had injuries, but not to his hand or wrist. Moises Alou preferred to drop a finger over the knob, but all those nicks and cuts he had throughout his career mostly happened to his legs. You could say the same about Chipper Jones, too. Bobby Abreu has been fairly healthy.

And so on and so forth, without any estimable conclusion. The subject seems almost impossible to figure.

If you admit that you are sampling selectively, though, you can take a different angle at the situation. In the last ten years, 49 non-pitcher players have had multiple visits to the DL for hand and wrist issues. 20 of them grip the bat on the end.

Even this more compelling number is fraught with problems. The sample is relatively small. It is perhaps biased towards players that are injury-prone. These players could have been hurt by anything — a hit-by-pitch, a botched grounder, a foul ball at the plate — and this isn’t necessarily because of their grip. But look at Jayson Werth, Jed Lowrie, Mark DeRosa, Michael Cuddyer, and Nick Johnson, and the list gains a sort of illegitimate legitimacy.

Let’s say it’s possibly a bad idea to grip the bat like this — obviously the Athletics think it might be. Why would players do it. Easy — leverage. Professor Alan Nathan is known for his work on the physics of baseball. He told me the reasoning, and the flaws as he saw them:

If the batter swings the bat by rotating it about some point near the body, then getting the barrel of the bat as far from the body as possible will get the highest bat speed in the barrel (which is where it counts). One way to do that is to grip the bat so that the hands overlap the knob. Of course, this whole thing assumes that the batter can rotate the bat as fast in that position as in the normal position. This kind of thing is not so uncommon in slow-pitch softball, where bat “quickness” (the ability to get around quickly) is not a big problem. I suspect it is not so common in Major League Baseball.

And indeed, if you search the internets for talk of ‘knob-grabbing’ — make sure your SafeSearch is on — you get many forums talking about the benefit of the grip in slow-pitch softball, where the need for power trumps the need for contact. But it does seem at least semi-prevalent in the majors, so there are those that choose to see past the risks for the power.

In the case of Cespedes, the power seems obvious — it’s drool-inducing to many — but the numbers so far (.189 isolated slugging, 15.4% swinging strike rate, 24.4% strikeout rate) seem to suggest that while he could benefit from making more contact, a power dropoff would bring his overall batting line much closer to league average.

Those players that choose to grab the handle at the knob do so for the extra power, knowing that it may have some adverse effects. Bat control, the ability to turn the bat quickly, and maybe even susceptibility to hand and wrist injuries — these may be the things they are willing to trade for the barrel speed and the power they seek. After all, by making it to Major League Baseball, they showed that they have most of those risk factors mostly in hand, and it’s the power that brings the bigger paychecks.