The Stiff vs. Flex Handle debate is the centerpiece of the dispute between baseball bat manufacturers and a leading cause of confusion among baseball bat consumers. I wish Mythbusters had included this in their baseball special. At least they taught us a corked bat actually reduces batted ball speed.
Here’s how to understand the rating for baseball bat handles. 100 is the stiffest handle rating and a handle with maximum flexibility will have a rating of 60. You’ll see ratings anywhere between these two extremes. Unfortunately, the majority of manufacturers do not provide the exact flex rating for their bats, just that they are stiff or flex handles.
Manufacturers like Easton and Demarini have pushed the benefits of the flex handle design for years, while others like Louisville and COMbat push the benefits of the stiff handle design. Two completely different designs stating they’re superior to the other. Will someone please hit me in the head with either a stiff of flex handle bat? Some manufacturers, like Easton, have recently begun to offer both flex and stiff handle versions of the same bat.
The flex handle philosophy says it’s better because “whip action” allows the bat to uncoil and release energy stored during the swing and increases the bat speed up to the moment of impact. Whip action is the bending of the bat when brought back and then swung forward before the point of contact. The top of the barrel is supposed to move behind the handle when it’s brought back and then move in front of the handle when it’s swung forward. Think of a diving board and a golf club as examples. See photo demonstrating the whip action of a golf club.
Stiff handle manufacturers say that stiff handles allow the trampoline effect in the barrel to be more effective thus improving batted-ball speed. The premise is all bats flex on contact (which is true) but the stiff handle makes that barrel flex more pronounced on contact and increases batted ball speed. Also, that rigid handles hit balls faster because a flexible handle messes up your swing, and if not timed exactly right, can actually reduce batted ball speed.
The current perception (or myths) of baseball bat handles amongst players and coaches is that power hitters prefer a stiff handle while contact hitters prefer a flex handle design. There is no scientific evidence supporting this preference but it is the accepted belief of the masses.
So who’s right? The answer is NOBODY because there is NO conclusive scientific evidence that shows a flex handle bat actually flexes prior to contact. The most detailed studies have been conducted by scientists at Kettering University and here is what they have to say:
“At this moment in time, I don’t believe that strain curves showing the strain in the handle during the swing provide sufficient evidence of a diving board mode that could cause whip action. Granted, I have not yet investigated this effect in some of the more flexible composite handled bats currently available. However, even in a composite handled bat I don’t believe whip action would be significant enough to actually influence the collision between bat and ball. If handle flex were significant enough to noticeably increase batted-ball speed I would expect the handle flex during the swing to be large enough that it could be observed in a high speed video of the swing. But, so far – after studying more than a dozen very clear overhead shots of baseball and softball players swinging “flexible” handle bats – I have not been able to detect any noticeable flexing of the bat prior to impact. Therefore, I have a very hard time believing that a typical softball or baseball bat will flex enough to be noticed during a swing.
In a nutshell Kettering is saying that any baseball bat handle is too thick to produce whip action thereby busting the primary stated benefit of a flex handle bat. The only potential benefit they mention is that a flex handle may be more forgiving if you do not hit the ball on the sweet spot. Nonetheless, there isn’t any scientific evidence showing a clear benefit for either a stiff of flex handle design.
My recommendation is the handle flex should be near the bottom of deciding factors in choosing a baseball bat. You should first decide on the material, a balanced or end loaded design and a one or two-piece bat. Then take a look at the handle and you’ll probably only have one option which is fine. But if the manufacturer offers both a stiff and flex handle bintang 4d version of the same bat I would choose the stiff handle version. The stiff handle version is always more popular than the flex handle version of the same bat. For example, the old Easton Comp, new Easton Stealth Speed and new Easton SV12 come in both stiff and flex handle designs. The stiff handle version of these bats are more popular. The fact that Easton, historically a leader in pushing the flex design, makes these stiff handle versions is telling in my opinion. In fact they promote the stiff handle Synergy Speed as providing increased balance and bat control through the hitting zone versus the Stealth model.