A bit more about the new rule regarding maple bats

Wendy Thurm: Can you tell me how the rule came about (i.e., was it a compromise between owners and players, what other changes were considered)?

Jason@IIATMS: Nearly everything in the CBA represents a compromise of some sort. Heck, if one side wanted to mandate that the sun rises in the East, the other side would try to negotiate that away. I am sure it was the only compromise the MLB, MLBPA, USDA, and equipment manufacturers could come up with to show due diligence in an attempt to improve or search for a solution.

As for the exact circumstances of the genesis of the rule change, I am not sure, but certainly this is an issue of importance for MLB. Unfortunately, in my opinion, this is mostly cosmetic to show us that they are trying to do something about the problem. However, I don’t believe it is enough. The Tyler Colvin incident could have been worse, far worse, and it just might take that worst case scenario to occur (to a fan or a player) to really get this problem fixed. That’s the scary truth. Had Colvin been a player like an Albert Pujols rather than a lesser known player across the non-hardcore baseball universe, greater change may have already been in effect. Thankfully, no one has been killed, but the list of injuries is mounting.

I’ve been as outspoken as anyone about this issue and a number of potential solutions have been developed. Some include radical multi-piece bats that will likely never see a major league game (see MLB Rule 1.11) as they fundamentally change the time-honored equipment of the game, not to mention the almighty statistics. Other solutions include ultra-thin polymer films that wrap the bat to keep the barrel and handle in place should the bat suffer what the manufacturers call a “multi-part failure”. Some of these have been tested at MLB facilities whereas others are merely entrepreneurial stabs at best.

Of course, there are other ways to remedy this problem without anything on the bats, but so long as the players want the thin handle, heavy barrel bats that create a whip-like action, bats will continue to shatter. According to MLB regulations, the difference between the bat length and weight can be no greater than 3.5. In other words, a 35” bat cannot be lighter than 31.5 oz. Bigger barrels, narrower handles and bats that push the limits of this rule (or exceed them due to player modification (sanding the handles for weight/narrowness) all greatly contribute to this problem.

So why does a maple bat shatter at such a greater frequency than ash? Let’s take a peek about the physiology of the wood in question… maple vs. ash.

First, some have noted that the surface area of maple is 20% harder than ash (others have noted that it’s only 4% harder), which would help the ball jump. Ash can create a springboard effect too, but because of their grain, ash doesn’t shatter like maple, they simply wear out and crack. One site has a good description:

Cracks form in both types of wood as a bat is used to hit ball after ball after ball. But the same pore structure that makes ash prone to flaking also channels cracks along the length of the bat, meaning the crack has a long way to grow before it can break the bat in two. And batters tend to notice the cracks or decide the bat has too much flaking and switch to a new bat before the old bat completely breaks.

Because of maple’s diffuse pores, cracks in the wood can grow in any direction, making it easier for them to grow out toward the edge of the barrel, causing a large chunk of it to break off entirely. And since maple doesn’t flake, serving as a warning to a player that his bat is cracking, “you’re perhaps more likely to have bat particles flying through the infield.”

This creates the danger.

When the ruling about the ban of low-density bats came to light, the president of the Sam Bat company (a leading maple bat manufacturer) had this to say:

“Basically, what we’re talking about is the weight of the wood, the volume of the wood that is used for a particular model. Certain players love to have what they call a big-barrel bat, lots of meat on the barrel, but then very lightweight wood. So the problem, of course, is when you create a larger barrel and you still want to have the bat very light, the wood density has to give. This is something though that most manufacturers will recognize as not being the strongest product.”

The lower density maple provides the hardness and is lighter than higher density maple, thus allowing more wood in the sweetspot at the same weight. This also increases the whip-like effect thanks to narrow handles.

So is it the wood density or treatment of the wood itself? Or both? Looking back at this 2008 article, the maker of the Sam Bats, Sam Holman indicated that some maple might not be pre-treated properly:

If you leave any moisture content in maple, you leave stress in the maple. If you have stress in the bat, it will break.”

Or is it the climate? One bat manufacturer noted this impact (despite their inability to spell check their website, sic’d everywhere):

“Climate conditions also effect proformance of the finished bat. In cold climates maple has a tendency to “explode” at the point of contact. This is caused by temperature as well as humidity and their effect on the cell structure, the Flexibilty of the wood fibers and moisture content. The combination of near freezing temperatures and less flexibility caused by reduced moisture content will result in a higher number of broken or “exploding” maple bats. During the summer months increased humidity levels will effect weight and flexibility as well. Humidity (moisture) is absorbed by the fibers of the wood. This process is referred to as equaliation with the end result being equalibrium moisture content. This level of moisture content is a naturally occurring process. In short, wood will equalize to the ambient conditions. This process will cause the weight and moisture content of a finished bat to fluxuate. This condition is the very reason many players are storing their game bats in a climate controlled areas or large humidors. Although ash is also effected by these conditions the end result doesn’t seem to be as drastic.”

Wendy Thurm: Will high-density maple bats be safer?

Jason@IIATMS: I asked Steve Rauso, founder of the BatGlove product, to explain the density issue to a non-scientist (like me). He was good enough to reply:

It is my opinion that low density wood would not carry as much vibration as high density wood. This would make for a sweeter pop. I do not know if the flight of the ball is affected however it does give you the “on the screws” feel, so I have been told by players. (I have nothing based in science to support this other than players’ comments regarding the two types in question.) Less density would mean more chance for an explosive break. The option to eliminate the LD wood is a step in the right direction. 

“The low density maple is a main reason players use maple.  It allows to players to use a higher density wood (maple vs. ash) without changing the weight of the bat, which greatly contributes to bat speed. This is what players want. If a low density maple bat is the same weight as a same size ash it will give the player the ability to swing a harder wood which would be an advantage to swinging ash. By eliminating low density maple and going to high density this would make for a heavier bat. This would slow the bat speed to player. The higher density wood brings with it the disadvantage of swinging a heavier bat.

[For a deeper dive into wood bat science, you can check here, too.]

There is a solution out there that does not change the bat performance and has been approved by Lowell UMass (pdf link to the full MLB-approved test and result here). This solution has also been given a green light by MLB for the lower levels of the minor leagues. However it will not be made a requirement because MLB does not tell manufacturers how they should build their products or conduct their business. Remember, it’s about the money. Always is.

All that being said, this rule is indeed a step in the right direction. Not a huge step, but a step forward. MLB will never be mistaken for a fast-acting, pre-emptive organization (cough, PEDs, cough). Sadly, I still believe it will take a more catastrophic incident to enact greater change. I hope I am wrong.

Additional resources: 

 FYI: I have no formal (or informal) business relationship with any company or product discussed above.

IIATMS overlord and founder. ESPN contributor. Purveyor of luscious reality.

4 thoughts on “A bit more about the new rule regarding maple bats

  1. LarryAtIIATMS

    I love Wendy Thurm. In a platonic way, of course. I want to ask Wendy, where have you been all my life? In a platonic way, of course.

    • I've been here all along, Larry. You must not have been looking in the right places. :)

  2. michael

    Will switching to heavier bats contribute to more effective pitching and less scoring?

  3. GabeLezra

    This…is pretty epic. Well done all.

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