It’s the bottom of the ninth inning, bases loaded with two outs, tie game. Aroldis Chapman is on the bump and he’s feeling himself. He just blew three straight fastballs by the previous hitter. You’re walking to the plate with the game on the line, and your coach is yelling at you from the top step of the dugout. As if you didn’t already have enough on your mind, You hear, “Shorten up,” “Stay within yourself,” and, “Be on time for the fastball.”
You think to yourself, “Thanks so much for your awesome help, Coach, I never would’ve thought of that without you.”
You try to tune it out and lock into your at-bat. You step in, putting your back foot as far back in the box as possible. You know you’re beaten and your only chance is to start your swing sooner to jump a heater, but what if there were a physical adjustment you could make to give yourself a better shot? Maybe simply changing the way you hold the bat would give you a better chance to run into a 100 mph fastball at the top of the zone.
What if the situation were completely different? What if you were facing a pitcher throwing nothing but nasty sliders at the bottom of the zone? With an influx of hitters in the gym during the winter, we decided to look into it.
How does a physical adjustment, in this case, hand position or grip type, impact the way a hitter swings the bat?
I wasn’t sure exactly what we would find but assumed the way a hitter holds the bat has to be important. The results of this study indicated just that.
To test how swings change with varied grips, we had thirty college and professional hitters (22 college and eight professional) take ten swings with each of four chosen grips: normal grip, pinky off (“choked down”), choked up, and a split grip.
We measured swing path and speed characteristics with a Blast Motion sensor on a round-knob 33- or 34-inch wood bat. We defined the normal grip as a traditional hand position, with the pinky of the hitter’s bottom hand touching the knob, and the pinky of the top hand touching the bottom hand. Pinky-off was when the hitter’s pinky hung off the end of the knob, leaving the athlete holding the bat lower than a normal grip. The choked-up grip was a normal grip shifted an inch higher toward the barrel, and a split grip was a normal grip with about an inch between the hitter’s bottom hand and top hand.
To avoid all confounding variables including fatigue, comfort and timing with the machine, and other factors that change during the season, the order of the grip type was uniquely randomized for all swings for each athlete, using experimental design software. Before each pitch, we instructed the athlete on which grip to use. The forty total swings from each participant were separated into 3-4 sets of 10-15 swings to alleviate the effects of fatigue.
We recorded data in the Blast Motion mobile application and downloaded it after data collection from the online Blast Connect dashboard. A linear mixed-effects model tested for differences in means of the various grip types for each of the recorded swing characteristics measured by the Blast system. The mean and standard deviations of each metric and hand position are reported in the table below.
All metrics include at least one significant comparison. This type of statistical test looks at the variance of all conditions and tests for significant effects of the grip types by evaluating how much variance is due to the condition (grip type) and how much of the variance is due to error or noise. This results in a level of significance and a magnitude of variance that is explained by the grip type that is used.
We used further analysis for all significant metrics to determine specifically which grip types differed from one another. Since every metric was significant in the statistical model, more (post-hoc) testing was done to find exactly which comparisons were different. For example, the statistical model found that bat speed was significantly affected by grip type. Further analysis found that normal grip and pinky-off grip showed significantly greater bat speeds than a split grip and a choked-up grip.
See a full list of significant comparisons in Table 2 below.
As for differences that stood out the most, metrics that describe the dynamics of the bat (speed, acceleration, etc.) showed clear differences between hand positions.
The bar graphs below illustrate the differences seen in bat speed, rotational acceleration, and time to contact between the hand positions. You can see athletes swung the bat with a higher average bat speed using a normal and pinky off grip, as shown in the bat speed comparisons, but they were much quicker to the plate with choked-up and split grips, as shown by the rotational acceleration and time to contact comparisons.
Which raises another question. What good are bat speed and quickness if the bat is not attacking the pitch at the proper angle? In the following bar graph’s you can see that attack angle is also significantly affected by hand positions.
Mean and standard deviations for bat speed, rotational acceleration, attack angle, and time to contact. * represents a significant difference between the corresponding grip type and the non-marked grip types. For example, choked-up, normal, and pinky-off grip attack angles were all significantly greater than split grip attack angles.
Measuring the Data
Let’s take a deeper look at the results for each of the individual metrics provided by the Blast Motion sensor. We’ll also look at how each metric is measured.
Bat Speed: The speed of the sweet spot of the bat at contact.
Bat speed was significantly higher for the normal and pinky-off grips. This makes a lot of sense as far as physics goes. The swings with the longer lever (normal and pinky-off) produced the highest bat speeds. So, if you’re looking to hit the ball harder and do damage, try these two grips.
- Normal – 72.3 mph
- Pinky-off – 72.0 mph
- Choked-up – 70.5 mph
- Split grip – 70.4 mph
Rotational Acceleration: How quickly the bat accelerates into the swing plane.
The choked-up grip showed the highest rotational acceleration by a good amount; the other three grips were fairly close together. Again, this makes sense in terms of physics. The grip with the shortest lever was the easiest to accelerate.
- Choked-up – 17 g
- Normal – 15.8 g
- Split grip – 15.2 g
- Pinky-off – 14.9 g
On Plane Efficiency: The percentage of the swing during which the bat is on the swing plane, established by the vertical bat angle at contact.
These are all fairly close together, but the longer the lever, the longer the bat is on the swing plane.
- Pinky-off – 69.5%
- Normal – 67.2%
- Split grip – 66.9%
- Choked-up – 65.2%
Attack Angle: The angle of the bat’s path at contact. Zero would be parallel to the ground, positive would be swinging up, negative would be swinging down.
The launch angle on a hitter’s hardest-hit balls is essentially going to match their attack angle. For example, if a hitter’s attack angle is 10 degrees, then their hardest-hit balls are going to be around 10 degrees. So, to consistently hit the ball harder in the air, pinky-off and normal grips are likely the grips for you because they resulted in higher attack angles. Knowing this information could play a large role in making adjustments against pitchers with high spin rates or a lot of vertical break.
- Pinky-off – 14.9°
- Normal – 14.4°
- Choked-up – 13.5°
- Split grip – 11.8°
Early Connection: Relationship between the body’s tilt and the vertical bat angle at the start of the downswing (first move). 90 degrees is ideal.
Early connection scores were all within what we consider a “good” range, but they were closest to 90 degrees with the pinky-off and normal grips. This makes some sense, assuming there is going to be some more “lag” of the barrel with the longer lever grips.
- Pinky-off – 92.7°
- Normal – 94.0°
- Split grip – 96.0°
- Choked-up – 96.4°
Connection at Impact: Relationship between the body’s tilt and the vertical bat angle at contact. 90 degrees is ideal.
For connection at impact, we see the exact opposite results from the early connection scores. The idea is that with the shorter lever grips (choked up and split grip) the barrel will be higher in space at contact and closer to the ideal 90 degrees at contact.
- Choked up – 85.8°
- Split grip – 84.9°
- Normal – 81.0°
- Pinky off – 79.7°
Power: Power generated by the swing. Found from the mass of the bat, bat speed at contact and the average acceleration during the downswing.
The power metric directly correlates to bat speed. So, it makes sense that the grip with the highest average bat speed (normal) produced the highest power score. Bat length also plays a big role here, so there would have to be some more investigation and potentially a bigger sample size to conclude this metric specifically.
- Normal – 4.66W
- Choked up – 4.53W
- Pinky off – 4.50 W
- Split grip – 4.48W
Time to Contact: Time elapsed between first move and contact.
Time to contact is closely correlated with the point of contact. It makes sense that when the bat is shorter, the point of contact is going to be deeper in the zone. Conversely, with the longer lever grips (normal and pinky-off), contact will have to be made further out front. When taking rotational acceleration of each grip into account, the choked up grip had the fastest time to contact and the highest rotational acceleration.
- Choked-up – 0.145 sec.
- Split grip – 0.146 sec.
- Normal – 0.148 sec.
- Pinky-off – 0.151 sec.
Peak Hand Speed: Max speed of the handle of the bat during the swing (measured six inches from the knob).
These are all pretty close together, but the choked-up grip showed the highest average peak hand speed. However, the choked-up grip has the lowest efficiency (bat speed/hand speed), which is a measure of how well you turn hand speed into bat speed. The highest efficiency metric came from a normal grip (72.3/21.9 = 3.30).
- Choked-up – 22.4 mph (3.15 efficiency)
- Normal – 21.9 mph (3.30 efficiency)
- Pinky-off – 21.8 mph (3.30 efficiency)
- Split grip – 21.6 mph (3.25 efficiency)
What does all of this mean?
There are a lot of variables to take into account when drawing conclusions from this information. Comfort is the most salient. Some of these hitters use these grips all the time. To see a hitter using a split grip in a game is pretty rare, but it happens. It’s fairly common for hitters to hang their pinky off the knob and choke up on the bat, and the normal grip is just as it sounds. Pretty normal. So, when looking at these results, factoring in what each hitter is most comfortable with is pretty important.
Something else to think about in the future is the bat itself. That’s probably pretty important, right?
Mixing in different handles (like an Axe Bat) could seriously change these results, but that’s a study for another time. In the meantime, here’s a blog post on bat fitting written by one of our hitting trainers, Collin Hetzler. The type of bat was not a factor in this particular study, as we used the same model bat (33-in. and 34-in.) with a traditional circular knob for this entire study.
The normal grip is probably the best grip to use. Without taking the hitter’s preference into account, the normal grip gives you the biggest bang for your buck. It produced the highest average bat speed, which is important. Check out our blog on why bat speed is important. The normal grip showed higher rotational acceleration than pinky-off (second highest bat speed), highest power and solid time to contact, and didn’t show any glaring issues with any of the other metrics.
Pinky-off is best suited only for those that are the most comfortable with it. Hitting is hard and being comfortable with how you are holding the bat will go a long way. With that said (I’m talking to you, coaches), if one of your hitters uses this grip and is successful, you should leave it alone. Time to contact and rotational acceleration are low with this grip, but bat speed is good. This could be something to play around with against slower arms or someone that lives at the bottom of the zone. Maybe give this a shot against the “crafty lefty” mid-week starter that’s going to spin you to death.
The choked-up grip can be pretty valuable depending on the situation. While bat speed and power potential were low, adjustability and barrel control could be improved using this grip (My juco coach would be fired up). Rotational acceleration and peak hand speed was high, time to contact was good, attack angle was lower and the connection angle was closer to 90 degrees at impact.
So, choking up could be beneficial when you’re facing someone throwing fuel, or if you are behind in the count looking to control the barrel. The difference is real but slim, so if choking up is uncomfortable for you as a hitter, it might not be worth it. If you’re a hitter with a coach that requires you to choke up with two strikes, do it and get the job done (as we say at Driveline, “Hitters hit”).
The split-grip had similar results to the choked-up grip: low bat speed, the lowest attack angle, quicker time to contact and a connection angle at impact closer to 90 degrees. That said, this grip is funky and pretty uncomfortable (according to the hitters in this study). It’s valuable as a drill when a hitter has a weak top hand, dumps the barrel and misses balls underneath. It might be worth switching to a slight split grip when facing a pitcher that lives up in the zone or has a high spin rate and/or high vertical break on their fastball.
Overall, each grip showed some significance. Disregarding the individual’s comfort level with each grip, the normal grip seems like the best grip to use. However, the goal is to be a good hitter. Getting blown away by fastballs? Adjust. Try choking up and improve your time to contact and rotational acceleration.
If you’re swinging underneath 87 mph heaters at your belt like your bat is made of swiss cheese, try adjusting your sights. If you want to go down the vision rabbit hole, here’s another blog post on gaze tracking research and how hitters see the ball.
You could also look into the five-part perception series on DrivelinePlus. All of these hand positions are valuable in their own right, and they can all help you as a hitter. If any of them are new to you, then play around with them in practice and see what you think.
Thanks for reading, good luck and go find some barrels.
By Tanner Stokey and Kyle Lindley