A single at-bat pitcher vs. batter duel built with macroquad 0.3 + egui-macroquad 0.14.
You control both sides — press Tab to switch roles.
# Requires Rust 1.75+ (MSRV of macroquad 0.3 + egui 0.21)
# On Linux you may need: sudo apt install libasound2-dev libx11-dev libxi-dev
cargo run --releaseThe game runs on Windows, macOS, and Linux.
Data files are written to data/ next to the executable on first launch if they don't already exist.
| Input | Action |
|---|---|
| Mouse move | Aim crosshair — see "Aiming" below |
Space / egui "THROW" |
Throw pitch |
| Mouse scroll wheel | Cycle selected pitch |
1–9 |
Select pitch by number |
Tab |
Switch to batting mode |
Mouse click is intentionally not the throw trigger — it's freed up so aiming and scrolling through pitches never accidentally fires a pitch.
| Input | Action |
|---|---|
| Mouse move | Position PCI (batting cursor) |
Space |
Swing |
LMB / egui button |
Trigger AI pitch (skips the auto-pitch wait) |
Tab |
Switch to pitching mode |
Auto-pitch: toggle in the side panel. When on, the AI pitcher throws automatically every few seconds (adjustable) — no clicking required between pitches. The windup gives two visual cues: a calm blue "get ready" pulse early on, crossfading into a sharp multicolor flash right at release.
| Input | Action |
|---|---|
Space / Enter / LMB |
Advance from result screen |
| egui "Reload" button | Reload all data files without restarting |
The yellow crosshair shows where a generic straight fastball (90 mph, plain backspin, no side/gyro spin) would cross the plate if released toward that point. The pitch you've actually selected is thrown along that same release direction — but its own movement then carries it away from the reticle, just like a real breaking ball drifts off your intended spot. A 4-seamer stays close to the reticle; a sweeper or curveball will drift noticeably. You have to aim "into" the break.
Contact now plays out fully: the ball flies, bounces (with energy loss and spin bleed-off each impact, up to 4 bounces), and rolls to a stop or clears the fence. Small dust-puff markers mark each bounce point, and an orange ring marks where it finally comes to rest.
Batters can have a natural swing tendency, set per-player in players.txt:
trait_vert=up/down/none— rewards high or low contact (launch angle)trait_horiz=pull/push/none— rewards early (pull-side) or late (opposite-field) contacttrait_bonus= how strong the resulting power swing is
An "up + pull" hitter gets his power bonus from swinging slightly early
and under the ball — swinging late and on top of it works against his
natural stroke. The included batter_ai is set up as a mild pull hitter by
default; edit players.txt to change either batter's profile.
This is primarily a timing game. Missing the green PCI reticle by a bit costs less than it used to — contact quality now leans heavily on swing timing, with PCI accuracy only softly modulating it. Separately, if you position the PCI outside the strike zone (reaching for an off-plate pitch), you gradually lose power the further out you reach — the reticle itself tints from green toward orange/red as a visual cue.
- Popups now show distance in the result text, and the classifier no longer labels a well-struck, deep steep fly ball a "Popup" — a real popup has to actually be short and/or weakly hit; a towering shot with real carry now correctly falls through to the fly-ball / home-run logic.
- Fixed a rare bug where a hard-topped grounder could "sink through the ground" in the batted-ball simulation instead of bouncing.
- Fixed the strike zone box being drawn smaller than the actual called- strike boundary — some pitches that visually missed the box outright were being called strikes. The box is now drawn at its true rulebook size; the "touches the zone" leniency lives entirely in the decision logic (which expands the true zone by one ball radius), never in the box you see.
Home runs are no longer capped at the fence distance for their reported distance — the ball keeps flying under normal physics past the wall until it actually comes back down, so a real moonshot can post a distance well north of 450 ft instead of reading as "the fence distance plus a few feet."
The 7 non-battery defensive positions (1B/2B/3B/SS/LF/CF/RF) are shown as simple dots at their honest, no-shift positions. Ground balls, liners, and fly balls are no longer decided by exit velocity and launch angle alone: each ball's landing angle from home plate is compared against those same positions — hit close to a fielder's angle, it's more likely fielded for an out; hit into a gap between two fielders, it's more likely to sneak through for a hit. Harder contact and, for fly balls, less hang time both cut into a fielder's effective range.
Whichever fielder is responsible for the play animates from their honest spot toward the ball — converging on the landing point and stopping there for an out (the "catch"), or continuing on to chase it down at its final resting spot for a hit — so you get a visual read on why it went the way it did, not just a text line. Out descriptions also name the fielder ("Ground out to SS", "Fly out to CF").
Switch to pitching mode (Tab) and the camera flips to sit behind the
mound looking back at the plate, instead of the usual behind-the-plate
view — a proper reversed camera (turning 180° also mirrors left/right, so
a position that was on your right as a batter is correctly on your left as
a pitcher), not just a repositioned copy of the same view. Everything —
field, fielders, ball flight, aim reticle — re-renders correctly from that
perspective automatically.
Windup length now depends on role: pitching mode stays short and snappy (0.5s) so manual throws never feel sluggish, while batting mode keeps a full 1s windup — its "get ready" pulse still starts up to a second early, during the tail of the existing "Next pitch in Xs" auto-pitch countdown, so the extra length reads as anticipation rather than added wait.
Alongside the yellow "generic fastball" aim reticle, a light, translucent green marker and short approach trail now show where the pitch you've actually selected will really cross the plate, given the same release direction — a quick visual read on how much a breaking ball will drift off your aim before you commit to the throw.
Brief full-screen flourishes on the big moments — fire/embers on a
strikeout, an ice storm on a walk, a couple of lightning bolts on any hit,
and a short staggered fireworks show on a home run. All purely cosmetic;
disable them together in game.txt:
[fx]
enable_outcome_fx = 0
The ground is now properly zoned, concentric from home plate outward: infield dirt (and mound) sit inside a green outfield that runs out to the fence, with everything beyond the fence — foul territory corners, behind the wall — rendered as plain dirt/soil so the fence reads as a clear boundary. 1st, 2nd, and 3rd base are marked at their real 90-ft spacing with a faint baseline diamond, making it easier to visualize where a groundout, liner, or bloop single would land relative to the infield.
Tracks where the most recent ball in play first landed — drawn on top of the side panel, not behind it. The dot only appears once the on-field animation actually reaches that spot (it never shows the result before you can see it happen), and it stays put through any number of non-BIP pitches afterward, only getting replaced once the next ball in play similarly lands.
- Drag + Magnus (Sawicki & Hubbard 2003) — piecewise Cl model, gyro spin removed before computing lift
- 3-iteration aim solver — adjusts initial direction so the ball crosses the intended plate location
- Command noise — Gaussian scatter applied to aim before sim (configurable per pitcher)
- Batted ball — same aerodynamics; EV/LA/spray from a contact quality model
All tuneable constants live in plain key = value text files.
Edit them while the game is running, then hit Reload in the side panel.
Defines the pitch arsenal shared by both pitchers.
[pitch]
name = 4-Seam Fastball
key = FF # ID used in ai.txt and hotkey list
velocity_mph = 96
backspin_rpm = 2150 # + = lift (4-seam ride), − = drop (curveball)
sidespin_rpm = -350 # + = moves right (RHP glove-side), − = arm-side run
gyrospin_rpm = 200 # bullet-spin; reduces movement, adds no lift
Included arsenal: 4-Seam, Sinker, Slider, Sweeper, Curveball, Changeup, Splitter, Cutter, Forkball, Knuckle-curve, and Knuckleball.
The knuckleball is a special case: real knuckleball movement comes from seam-induced turbulence that the Magnus-lift model here doesn't capture. Any pitch with very low total spin (< ~350 rpm) instead gets a small random in-flight "flutter" — you can still aim it, but you can't fully control where it drifts, same as the real pitch.
Batter and pitcher attributes.
[batter_user]
side = R # R or L (handedness)
power_ev = 107 # max exit velocity (mph) on a perfect contact
pci_rx = 1.05 # PCI half-width (feet)
pci_rz = 0.55 # PCI half-height (feet)
[pitcher_user]
command_sigma = 0.35 # Gaussian noise on pitch location (feet at plate)
Ball constants and release point.
Strike zone dimensions, batting contact model coefficients, park fence distances, and view / camera parameters.
AI pitcher pitch-mix weights per count state, zone rates, and AI batter recognition / timing / PCI noise parameters.
The egui panel shows HB (horizontal break) and IVB (induced vertical break) in inches for each pitch, computed once at startup via a no-gravity control simulation.
- HB+ = moves toward the catcher's right (RHP glove-side)
- IVB+ = rises vs. gravity (backspin lift)
- Add new pitches to
pitches.txt(they appear automatically in the hotkey list and AI weights) - Tune
game.txttime_scale(< 1.0 = slow-motion) to practice recognition - Increase
pci_rx/pci_rzinplayers.txtfor an easier batting target - Tighten
ai.txtrecognition_sigmato make the AI batter sharper