To Bat or Not to Bat?

Batting Eye of Elite Batters: A Preliminary Report

Yin-Hua Chen, Yu-Wen Lu, Pei-Hong Lee and Nai-Shing Yen

Research Center for Mind, Brain and Learning, National Chengchi University,

No. 64, Sec. 2, Zhi-Nan Rd., Wen-Shan District, Taipei 11605, Taiwan

Keywords: Baseball, Batting Decision, Expertise, Action Anticipation.

Abstract: In this study, we investigated the difference of the batting decision in advanced (n=18) and intermediate

baseball batters (n=12) by asking them to make a swing judgement and then to recognize the pitch after they

viewed it, given a draw situation of full count (2 strikes and 3 balls), 2 out, and full base at the last inning in

a match. We also manipulated the length of the video sequence of the pitch that was presented to the batters

to investigate the group difference when batters could see only fraction of pitch motion and the baseball

trajectory. Advanced players showed higher batting rate than the intermediate players, particularly when

they could see very limited sequence of the strikes pitches. This result reflected their more accurate and

quicker response for strikes as compared to intermediate players. Interestingly, a similar tendency was also

found for ball pitches. This result could be explained by that advanced players considered those balls as

potential strikes subjectively; or that they were intended to make a foul ball, for getting a further pitch count

as a positive strategy. Intermediate players instead, in this situation were not sure whether to bat or not,

resulting a higher percentage of uncertain decision. We concluded that to make a batting decision correctly

and strategically could be important elements in achieving high level batting.

1 INTRODUCTION

In baseball, the batter has only a fraction of a second

to decide whether the pitch will be a strike or a ball

and whether he will swing the bat or not. It is of

great interest to understand whether these two

questions are considered as one question to batters

depending on different skill levels. Therefore, we

asked batters at different skill levels to make a swing

judgement and then to recognize the pitch after they

viewed it. We focused our attention in the batting

decision of the batters since the final goal of a batter

is to make a correct and successful attack by

swinging the bat rather than to make correct pitch

recognition.

It has been shown that both the motion of the

pitcher and the trajectory of the baseball are

important cues for batters in recognising the pitch as

well as in making the batting decision (e.g., Hubbard

and Seng, 1954; Shank and Haywood, 1987;

Takeuchi and Inomata, 2009). Therefore, we filmed

the pitcher’s motion from his preparatory phase until

the baseball reached the plate, from a right-handed

batter’s perspective. In order to see whether the

amount of the information of baseball trajectory

could influence the batting decision differently, we

then edited each pitch to show different lengths of

the baseball trajectory.

Previous studies have reported that expert batters

show significantly shorter decision time and higher

accuracy in recognizing the pitch and predicting

where the baseball will pass through the strike zone

(Paull and Glencross, 1997). Thus, we expected that

advanced batters would show the same tendency in

their batting decision as compared to intermediate

batters. Particularly, we investigated whether

advanced batters would be more aggressive in attack

(i.e., choosing to swing the bat anyway) even when

the forthcoming pitch was ambiguous in recognition.

2 METHODS

2.1 Participants

We recruited 18 advanced players (mean age=20;

training years=10.22; hours per week=23.94) from

highly ranked Taiwanese university baseball team

Chen Y., Lu Y., Lee P. and Yen N..

To Bat or Not to Bat? - Batting Eye of Elite Batters: A Preliminary Report.

DOI: 10.5220/0005144500340040

In Proceedings of the 2nd International Congress on Sports Sciences Research and Technology Support (icSPORTS-2014), pages 34-40

ISBN: 978-989-758-057-4

 2014 SCITEPRESS (Science and Technology Publications, Lda.)

(advanced skill-level group) and 12 intermediate

players (mean age=23; training years=6.84; hours

per week=9.42) in this study. Two third of the

advanced skill-level group had the experience of

participating in international competition. To qualify

for the intermediate skill-level group, participants

had to have played on their university faculty

baseball team. All participants were right-handed

males, and with the height about 180 cm to have

similar strike zone. This study was approved by the

Research ethics committee of National Taiwan

University and was in accordance with the

Declaration of Helsinki; participants gave written

informed consent.

2.2 Stimuli

The stimulus sequences were colour video clips

(wmv format) of baseball pitches of 2 skilled

pitchers. The 2 skilled pitchers were asked to throw

four-seam fastballs to the strike zone of a 180-cm

right-handed batter from the pitcher’s mound toward

the catcher, given a draw situation of full count (2

strikes and 3 balls), 2 out, and full base at the last

inning. The video sequences were taken from the

batter’s perspective using video camera (SONY

HDR-XR150; 30 frames/s; setting see Figure 1). 9

strikes in a nine-cell strike zone and 9 balls out of

the strike zone thrown by each pitcher were recorded,

making a total of 36 (2 pitchers x 2 types of pitch x 9

throws) different throws. Whether the pitch was a

strike or a ball was judged by a skilled catcher on

site. The criterion that we used to recruit the 2

skilled pitchers and the catcher was the same as the

criterion of recruiting the advanced skill-level

batters. The average speed of the throws was

controlled at around 115 km/hr by a speed gun. We

then edited each video in 12 different lengths, which

included the windup preparation phase and the

pitching phase till the moment of the baseball

released from the pitcher, or 33, 67, 100, 133, 167,

200, 233, 267, 300, 333, and 367 ms after the

baseball released from the pitcher, respectively.

2.3 Task

The task is twofold. Right after viewing the pitch,

participant had to decide whether he would swing

the bat or not (to bat, not to bat, or I don’t know) by

pressing the response key 1, 2, or 3 with index,

middle or ring finger. Immediately after this batting

decision, he had to recognize the pitch type (strike,

ball, or I don’t know) again by pressing one of the

response key with its corresponding finger. The

response key (1, 2, or 3) assigned to the answer of

batting decision (to bat, not to bat, or I don’t know)

were counterbalanced between participants.

Figure 1: The display of experimental apparatuses: the

blue filled box indicates the position of video camera.

The response key of the answer of batting

decision (to bat, not to bat, or I don’t know) was

always combined with the response key of answer of

pitch recognition (strike, ball, or I don’t know)

following the nature of batting a strike and not

batting a ball. All of the responses had to be made in

2.5 s, or the trial would be skipped. We reminded

participants to respond as quickly as possible, but we

emphasised accuracy over speed.

2.4 Procedure

Before testing, we demonstrated the video sequences

of the pitch of the 9 strikes and 9 balls of each

pitcher to the participant. The video sequences

demonstrated in this phase were longer than the

testing stimuli because they were terminated at the

moment of 200 ms before the baseball was caught

by the catcher. This procedure was applied to let the

participants familiar with the strike zone judged by

the catcher and to let participants adapted to the

scene filmed by the video camera. We then

explained the task to the participant. Participant

could practice at least 10 trials to make sure that the

task is fully understood.

ToBatorNottoBat?-BattingEyeofEliteBatters:APreliminaryReport

In each trial, the participant was presented with a

fixation cross displayed on a white background and

located in the centre of the screen (1024x768, 60Hz)

for 1 s. Next, the video clip of the pitch was played.

When the video clip terminated, participant had to

decide whether to bat or not and to recognize the

pitch type. The inter-stimuli interval (ISI) was 1 s

(See Figure 2). There were 432 (2 pitchers x 2 types

x 9 pitches x 12 video lengths) trials, randomly

divided into 8 runs, to be completed. Between each

runs, participant could have a short break of 3-5

minutes. The entire experiment took approximately

1.5 hr. The experimental protocol was written using

Eprime 2.0. The response and response time of

participants were registered for data analysis.

2.5 Data Analysis

We calculated the percentage of the response (i.e., to

bat, not to bat, uncertain) of each participant in each

experimental condition. A correct batting decision

included 2 situations: batting for strikes and not

batting for balls. An incorrect batting decision could

be “batting for balls” and “not batting for strikes”.

The data was then entered into 3 separate repeated-

measures mixed-model 3 way (2 groups x 2 types of

pitch x 12 lengths of video) ANOVAs for the correct,

incorrect, and uncertain batting decision,

respectively. For all ANOVAs, group was the

between-subject factor, and type of pitch and length

of video were within-subject factors. The threshold

for significance was set at p < .05. Furthermore, we

picked up 6 pitches that were considered the most

ambiguous pitches while batters were asked to

identify the type of the pitch. We then computed

again the percentage of decision of “to bat” between

2 groups and compared the group difference in

different lengths of video sequence using a 2 way (2

groups x 12 lengths of video) repeated measures

ANOVA. A Bonferroni adjustment was used for

multiple comparisons. SPSS 20.0 was used for

statistical analysis.

3 RESULTS

In Figure 3 we demonstrated the average percentage

of correct, incorrect, and uncertain batting decision

made by advanced and intermediate players for

strikes and for balls, after they viewed 12 different

lengths of video sequence of the pitch. All of the

statistics were reported in Table 1.

3.1 Correct Decision

The ANOVA (2 groups x 2 types of pitch x 12

lengths of video) detected a significant main effect

of type of pitch, with higher percentage observed for

the strikes than for the balls. We also found a

significant main effect of length of video, for the

percentage was higher when batters could see longer

videos. There was also a significant main effect of

group, with advanced batters showing higher

accuracy than the intermediate batters. Moreover,

we found a significant video length-by-group

interaction. It was due to the group difference was

significant when the video was short (from length 2

to length 5) but not when the video was longer (see

Figure 4 top panel). A video length-by-pitch type

interaction was also detected. This interaction effect

was due to the higher accuracy for the strikes than

for the balls was found particularly for long videos

(from length 6 to 12; see Figure 4 bottom panel).

The 3 way interaction effect was also significant, for

that advanced batters showed higher accuracy than

the intermediate batters, particularly when they

viewed the very short strikes videos (length 1 to 3).

Figure 2: The procedure of a trial.

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Table 1: Statistics of all main effects and interaction effects for correct rate, incorrect rate, and uncertain rate for all pitches,

and batting rate for ambiguous pitch.

Index Effect F value p value Pairwise comparisons

Correct

rate (%)

Group F

(1, 28)

= 7.28 p < .05 Advanced > intermediate batters

Pitch type F

(

)

= 29.43 p < .001 Strike > ball

Video length F

(

308

)

= 78.89 p < .001 Long > short

Video length-by-

group interaction

(11, 308)

= 4.03 p < .001

Group difference particularly in short

videos (length 2~5)

Video length-by-pitch

type interaction

(11, 308)

= 15.86 p < .001

Type difference particularly in long videos

(length 6~12)

3 way interaction F

(11, 308)

= 3.71 p < .001

Group difference particularly in very

short strikes videos

(length 1~3)

Incorrect

rate (%)

Pitch type F

(

)

= 30.54 p < .001 Ball > strike

Video length F

(

308

)

= 6.11 p < .001 Short > long

Video length-by-pitch

type interaction

(11, 308)

= 13.54 p < .001

Type difference particularly in not-short

videos (from length 4~12)

3 way interaction F

(11, 308)

= 3.45 p < .001

Advanced > intermediate batters,

particularly in short balls videos (length

1~2)

Uncertain

rate (%)

Group F

(

)

=6.89 p < .05 Intermediate > advanced batters

Video length F

(

308

)

= 53.26 p < .001 Short > long

Video length-by-

group interaction

(11, 308)

= 4.83 p < .001

Group difference particularly in short

videos (length1~4)

Video length-by-pitch

type interaction

(11, 308)

= 15.87 p < .001

Higher rate for the balls in extremely short

videos (length 1)

Batting

rate for

Ambiguous

pitch (%)

Group F

(

)

=3.47 p = .073 Advanced > intermediate batters

Video length F

(

308

)

= 17.56 p < .001 Long > short

Video length-by-

group interaction

(11, 308)

= 4.62 p < .001

Advanced > intermediate batters,

particularly in short balls videos (length

1~3)

Figure 3: Average rate of correct, incorrect, and uncertain batting decision made by the advanced and intermediate batters

after viewing 12 different video lengths. The 12 different video lengths showed the windup preparation phase and the

pitching phase until the moment of the baseball released from the pitcher, or 33, 67, 100, 133, 167, 200, 233, 267, 300, 333,

and 367 ms after the baseball released from the pitcher, respectively.

ToBatorNottoBat?-BattingEyeofEliteBatters:APreliminaryReport

Figure 3: Average rate of correct, incorrect, and uncertain batting decision made by the advanced and intermediate batters

after viewing 12 different video lengths. The 12 different video lengths showed the windup preparation phase and the

pitching phase until the moment of the baseball released from the pitcher, or 33, 67, 100, 133, 167, 200, 233, 267, 300, 333,

and 367 ms after the baseball released from the pitcher, respectively. (cont.).

Figure 4: The average correct batting rate of 2 groups (advanced vs. intermediate batters; top panel) for 2 types of pitch

(strike vs. ball; bottom panel) as a function of the length of video sequence of the pitch. *p < .05. Error bars indicate

standard errors.

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3.2 Incorrect Decision

In the 3 way (2 groups x 2 types of pitch x 12

lengths of video) ANOVA, we found a significant

main effect of pitch type, with higher percentage

observed for the balls than for the strikes. There was

also a significant main effect of video length, for

batters showing the lowest inaccuracy in the shortest

video (length 1) compared to other videos. The main

effect of pitch type interacted significantly with the

main effect of video length, for the difference

between the pitch types was not significant for the

short videos (see Figure 5). We also found the 3 way

interaction effect significant. The post-hoc analyses

indicated that advanced batters showed higher

inaccuracy than the intermediate batters, particularly

when they viewed the very short balls videos (length

1 to 2). The main effect of group and other

interaction effects were not significant.

Figure 5: The percentage of the decision of “Not to bat”

when batters saw different lengths of video of strikes

(shown in blue) and balls (in green). *p < .05. Error bars

indicate standard errors.

3.3 Uncertain Decision

The ANOVA for the decision of “I don’t know”

detected a significant main effect of video length,

showing that the longer the video the less uncertain

the batters. The main effect of group was also

significant, with intermediate batters showing higher

uncertain rate than the advanced batters. There was

also a significant video length-by-group interaction.

It was due to that the group difference was

significant only for the short videos (from length

1~length 4; see Figure 6 top panel). Moreover, we

found a significant interaction between the main

effect of length of video and the main effect of type

of pitch, F(11, 308) = 3.63, p < .001. It was based on

the fact that batters showed higher uncertain rate for

the balls when the video was extremely short (in

length 1) but not when the videos were longer (see

Figure 6 bottom panel).

Figure 6: The percentage of decision of “I don’t know” of

2 groups (advanced vs. intermediate batters; top panel) for

2 types of pitch (strike vs. ball; bottom panel) as a function

of the length of video sequence of the pitch.

*p < .05.

Error bars indicate standard errors.

4 DISCUSSION

In this study, we investigated the difference of the

batting decision in expert and non-expert baseball

batters. A correct batting decision is “to bat” for the

strike and “not to bat” for the ball pitch. We also

manipulated the length of the video sequence of the

pitch that was presented to the batters to investigate

the difference between the 2 groups when they could

only see fraction of the pitch motion and the baseball

trajectory. It is worthy to note that the pitching

videos were obtained by 2 different pitchers. It

provided more varieties as compared to previous

study that used pitch motion of only one pitcher.

ToBatorNottoBat?-BattingEyeofEliteBatters:APreliminaryReport

We found that advanced players made batting

decision with higher accuracy than the intermediate

players, particularly when they could see very

limited amount of strike trajectory. This result

indeed reflected the fact that advanced players were

more accurate and quicker in batting decision, due to

their more accumulated experience, as compared to

intermediate players. Interestingly, we also found

that advanced players chose to swing the bat after

viewing the very short ball pitches. This result could

be explained by that advanced players considered

those balls as “potential” strikes subjectively since

they only saw very limited sequence of the ball

pitches. It could be also possible that they were

intended to make a foul ball, for getting a further

pitch count as a positive strategy.

Intermediate players instead, while viewing

short pitch sequence (not matter for balls or for

strikes) was not sure whether to bat or not, resulting

in a higher percentage of uncertain response. In sum,

we found that advanced batters decided whether to

swing the bat or not even when they could see very

short pitching sequence. Intermediate players could

not make such decision if they could not see enough

baseball trajectories. When the pitch sequence could

reveal enough information for batters to decide

whether to bat or not, both advanced and

intermediate players could make more accurate

decision. This result was consistent with the

previous studies that players could better recognize

the type of the pitch when they saw the longer

trajectory of the baseball (Paull and Glencross,

1997).

The limitation of this study could be that we did

not consider the eye and head movement strategy

(Mann et al., 2013). However, our results provided

the evidence that to make a batting decision

correctly and strategically could be important

elements in achieving high level batting. We will

perform a further analysis of the batters’ decision

time to understand more deeply their batting

decision.

ACKNOWLEDGEMENTS

We would like to thank coach Shih-Kuei Huang

from Chinese Culture University, coach Wen-Nan

Liao from University of Taipei, coach Jung-Tang

Kung from National Taiwan Sports University, and

coach Po-Hsiu Lin from National Taiwan Normal

University for their help in recruiting baseball

players and their useful insights in experiment setup

and discussion.

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Aglioti, S.M., Cesari, P., Romani, M., and Urgesi, C.,

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Hubbard, A.W., and Seng, C.N., 1954. Visual movements

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Mann, D. L., Spratford, W., and Abernethy, B. 2013 The

head tracks and gaze predicts: How the world’s best

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Shank, M.D., and Haywood, K.M., 1987. Eye movements

while viewing a baseball pitch. Perceptual and Motor

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Paull, G., and Glencross, D., 1997. Expert perception and

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Williams, A.M., Davids, K., and Williams, J.G., 1999.

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F. N. Spon.

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