Ask pitchers why their bullpen stuff does not show up on game day and you hear about adrenaline and nerves. Both are real. There is also a quieter reason. In a game, a pitcher's delivery is organized around a stream of information: the hitter's stance, the catcher's target, the count, the runner leading off first, the clock. A typical bullpen strips almost all of that away. The pitcher is practicing a slightly different skill from the one he needs. (Our post on why pitchers throw strikes in the bullpen but not in games looks at the same gap from the practice-difficulty side.)
Remove information and the movement changes
The clearest evidence comes from cricket. Pinder and colleagues compared young batters facing a bowling machine with the same batters facing a live bowler at a matched ball speed of about 63 mph [1]. Against the live bowler, batters started their backswing and front-foot movement earlier and took a longer step. Against the machine, they moved later. A follow-up with skilled batters found that removing the bowler's action delayed movement and reduced peak bat speed and contact quality, and that video of a bowler without real ball flight changed timing in its own way [2].
Same ball speed, different movement. The information in the environment shapes the action itself, an idea researchers call perception-action coupling. Those studies are about batters reading bowlers, and the direction is reversed for pitchers, but the principle carries: when you remove key game information from practice, you change what you are practicing.
What is representative practice?
Scientists call the fix representative learning design. Pinder and colleagues argue that practice can be simplified, but it should keep the key information and decisions that drive performance in competition [3]. In practice, that means knowing which game information you have removed and bringing it back regularly.
For a pitcher, the key information usually includes:
- A hitter in the box, with a side and a stance.
- A real catcher's target that moves.
- The count and the runners.
- The clock.
Representativeness is a dial, too. In a junior tennis study, adding a returner to serve practice changed what players prioritized in matches, with placement favored over speed on second serves, and the effect was more nuanced than "more realistic is always better" [6]. The PoST skill periodization framework makes the same point: how game-like practice should be depends on the stage of learning [10].
Make the work happen
Schedule the pens that matter
Pitch AI schedules your bullpens and Command days, so the work actually happens instead of getting pushed to the end of the week.
How to bring the game into your bullpen
Put a hitter in the box
Start with a stand-in hitter who tracks pitches without swinging, wearing a helmet, alternating sides. Later, move to live at-bats and simulated games. Safety comes first: use a protective screen where appropriate and keep stand-in hitters out of a pitcher's early, wild sessions with a new pitch.
Call counts and keep score
Start each hitter at a set count, such as 1-1 or 2-1, have the catcher call balls and strikes, and make the pitcher finish the at-bat. Track zone rate and finish rate by count. A scoreboard turns a pen into a competition.
Add pressure on purpose
Pressure training has solid support, and our post on training to pitch under pressure covers it in depth. A meta-analysis of 14 studies, covering athletes and law enforcement officers, found that practicing under simulated pressure improved later performance under pressure, with moderate to large effects [7]. In one study, expert basketball players who practiced free throws under induced anxiety for five weeks no longer choked on an anxiety post-test, while a group that practiced without anxiety still did [8]. For pitchers, pressure can be as simple as a coach and teammates watching, points for strikeouts, a small consequence for walks, or a filmed "audition" pen.
How you frame the target matters under pressure. In a pitching study by Gray, Orn and Woodman, pitchers who were also shown a zone to avoid threw more pitches into that zone under pressure [9]. Give positive targets ("hit the glove") and skip the "don't leave it middle" cues.
Use the clock
MLB's pitch timer gives pitchers 15 seconds with the bases empty and 18 seconds with runners on [11]. If you will pitch with a clock, practice with one, and occasionally run it a little shorter than the game. Many amateur leagues now use some form of timer, so check your league's rules.
Change the environment
Throw some bullpens in wind instead of cancelling, rotate mounds and catchers, and take some sessions under lights or with different backgrounds. Changing conditions also tests whether your mechanics hold up when the setting shifts. Gray points out that a wet, windy day is free practice for game conditions [4]. These ideas are practical coaching suggestions; there are no controlled studies of cold, lighting or unfamiliar catchers on pitching.
A sample game-like bullpen
Here is one way to structure a 30-pitch pen for a high school or college pitcher who is already throwing full bullpens. It is a template to adjust to your workload plan.
| Block | Pitches | Setup |
|---|---|---|
| Warm-in | About 8 | Fastballs to a moving glove, no hitter, finish with two from the stretch |
| Stand-in hitter | About 10 | Hitter alternates sides; catcher calls pitch and location late |
| Simulated at-bats | About 12 | Every hitter starts 1-1; catcher calls balls and strikes; pitch timer on; a runner on first for half the hitters |
| Score | All | Outs earned and walks allowed; post the result where teammates can see it |
Count every pitch in your workload, including the warm-in, and see our workload and arm health guide for how those pitches add up. A game-like pen is a higher-stress session than a blocked pen of the same length, so treat it as one of the harder days of the week.
The indoor targeting problem
Offseason throwing often happens indoors, into nets, at a catcher in the corner of a cage. On Rubicon's "Casting the Die" podcast, the host and Cubs strength coach Steffen Simmons argue that indoor targeting is an underrated command problem: with no open space behind the target and every miss caught by a net, pitchers rarely see a wild throw, and 60 feet of open field can suddenly look very long in spring training [5]. They suggest offseason setups where missed balls must be chased, with targets that have space behind them, and throws of at least 45 feet so the ball's flight is visible [5]. That is practitioner opinion, and it is easy to test in your own facility.
Even labs notice the difference
Biomechanics researchers see the setting effect too. Comparing pitchers in a laboratory with pitchers in games, Lerch and colleagues note that pitchers typically throw slower in a lab than in games, and found that two of ten arm measures varied more in games [12]. The comparison used different pitchers and different capture systems, so it is not a clean bullpen-versus-game test. It does show that the setting a pitcher throws in is part of the skill.
No controlled study has compared pitchers throwing with and without a hitter in the box. The case for game-like bullpens comes from batting and cricket research plus pressure training studies. That makes it a smart, well-supported bet, and a pitching-specific test is still missing.
Keep some simple pens, too
Blocked, low-stakes bullpens still have jobs. They are useful for early shape work at low stress and for building confidence before a start. Rubicon's guests describe blocked work right before competition as fine for confidence, and too thin as the main way to learn [5]. The mistake is making every pen a blocked pen. Plan a mix through the week, with the most game-like sessions sitting where they have room to be hard. Our weekly training schedule shows how to place them, and throwing program progression covers the flat-ground to mound steps that come first.
What to do this week
Take one bullpen this week and add two things it is currently missing, such as a stand-in hitter and called counts. Score it, then compare that score with your next game's strike rate and first-pitch strike rate. Build the rest of the week with the task dials from Part 2, and when you are ready to take a new pitch into competition, read Part 4. New to the idea? Start with Part 1 on the constraints-led approach.
Frequently asked questions
Why do pitchers pitch worse in games than in bullpens?
Part of the reason is that bullpens remove information pitchers react to in games, such as a hitter, a moving target, the count, runners and the clock. Research in batting and cricket shows that removing key information changes how athletes move.
How do you make a bullpen more game-like?
Add a stand-in or live hitter, have the catcher call counts and locations, keep score, add mild pressure such as an audience or consequences, use a pitch clock, and vary mounds, catchers and weather.
What is representative learning design?
It is the principle that practice can be simplified but should keep the key information and decisions from competition, so the skill you train matches the skill you use in games.
Is there research on pitching with a hitter in the box?
Not directly. No controlled study has compared pitchers throwing with and without a hitter. The recommendation is based on batting and cricket research plus pressure training studies.
Game-ready practice
Plan your bullpens with Pitch AI
Pitch AI schedules your bullpens and Command days inside your throwing program, logs every throwing session so workload builds progressively, and tracks the intent of every set so game-like pens and recovery days stay distinct.
References
- Pinder RA, Renshaw I, Davids K. Information-movement coupling in developing cricketers under changing ecological practice constraints. Human Movement Science. 2009;28(4):468-479. doi:10.1016/j.humov.2009.02.003
- Pinder RA, Davids K, Renshaw I, Araújo D. Manipulating informational constraints shapes movement reorganization in interceptive actions. Attention, Perception, & Psychophysics. 2011;73(4):1242-1254. doi:10.3758/s13414-011-0102-1
- Pinder RA, Davids K, Renshaw I, Araújo D. Representative learning design and functionality of research and practice in sport. Journal of Sport and Exercise Psychology. 2011;33(1):146-155. doi:10.1123/jsep.33.1.146
- Gray R. How We Learn to Move: A Revolution in the Way We Coach & Practice Sports Skills. 2021. Chapter 4.
- Rubicon. "Casting The Die | Episode 2 | Steffen Simmons." YouTube, 2026-09-19. youtu.be/PkRCz3dhYn0
- Krause L, Farrow D, Pinder R, Buszard T, Kovalchik S, Reid M. Enhancing skill transfer in tennis using representative learning design. Journal of Sports Sciences. 2019;37(22):2560-2568. doi:10.1080/02640414.2019.1647739
- Low WR, Sandercock GRH, Freeman P, Winter ME, Butt J, Maynard I. Pressure training for performance domains: a meta-analysis. Sport, Exercise, and Performance Psychology. 2021;10(1):149-163. doi:10.1037/spy0000202
- Oudejans RRD, Pijpers JR. Training with anxiety has a positive effect on expert perceptual-motor performance under pressure. Quarterly Journal of Experimental Psychology. 2009;62(8):1631-1647. doi:10.1080/17470210802557702
- Gray R, Orn A, Woodman T. Ironic and reinvestment effects in baseball pitching: how information about an opponent can influence performance under pressure. Journal of Sport and Exercise Psychology. 2017;39(1):3-12. doi:10.1123/jsep.2016-0035
- Otte FW, Millar SK, Klatt S. Skill training periodization in "specialist" sports coaching: an introduction of the "PoST" framework for skill development. Frontiers in Sports and Active Living. 2019;1:61. doi:10.3389/fspor.2019.00061
- Major League Baseball. "What to know about MLB's rule changes for 2024." MLB.com. mlb.com/news/mlb-rule-changes-for-2024
- Lerch BG, Fleisig GS, Slowik JS, Oliver GD. Variability of in-game markerless and laboratory marker-based baseball pitching biomechanics. Journal of Biomechanics. 2025;188:112775. doi:10.1016/j.jbiomech.2025.112775