Play Online
Race Derby Owners Club against other owners online, right in your browser: no download, no setup. Watch the live cabinets, sign in with a free account, and take an open seat to play in real time with your own stable. Two cabinets are running now, an 8-player and a 6-player; when every seat is taken you can join the line and the next opening routes you straight in. There's an arcade-wide chat too, so you can talk between races.
▶ Enter the Arcade play.johnreevesiii.com (opens in a new tab) Join our Discord community chat between races, find people to play, plus records & helpAnyone can watch the live races. Taking a seat to play just needs a quick free sign-in.
Play at Home
A full arcade row on one PC
Community members can now run the real thing at home: the big two-screen race board plus 4, 6, or 8 player seats, all on one computer. The Host Pack is one download with all four game versions inside (World Edition Rev C, World Edition EX Rev D, DOC 2000, DOC '99). Run START HERE - Setup, pick your version and seat count, and from then on one desktop shortcut boots everything: the windows arrange themselves and the boards link up on their own, no clicking through screens.
No account is needed to play: rental horses wait at every seat. Record tables start fresh out of the box, so the first wins put your names up on your own big screen, and Submit My Records can send your best times to the community master board.
Get the Host Pack: it's distributed through our
Discord community —
join and type
/hostpack anywhere in the server for the download and login.Stable Link: your online stable, at your seats
The free companion that turns every seat into a card reader for the online stable. Run it next to the Host Pack and each seat gets a login code: a player opens play.johnreevesiii.com/seat-link on their phone, signs in (or creates a free account on the spot), enters the code, and their own horses ride at that seat. Tap a horse to insert it like a card, race, then Save and it gallops home to their online stable.
Your horses never live on anyone's computer. The online stable is the card; every seat is just a reader. Every save runs the exact same server checks as every cabinet in the lobby, so a horse raised in a living room counts exactly the same as one raised online.
Download DOC Stable Link
~15 KB · free · updates itself
Playing at someone's rig is free: rentals need no account, and riding your own stable needs only a free account. Pairing your own rig to the online stable is a Winner's Circle perk, same as hosting a cabinet.
Derby Owners Club is back, and it belongs to you.
DOC is more alive today than it has been in years: a real, open, community-run home for everyone who loves the game.
For years, playing Derby Owners Club at home meant knowing the right person or paying for a modified machine. That era is over. This is the open, free home for everyone who loves the game: no gatekeepers, no catch.
Look for the seal
The DOC Guarantee
Our promise to everyone who loves this game.
- ✓Free to play, always. The game, the arcade, and the tools never cost you a thing. For now we run on donations, working toward the real goal: a home hosted and supported entirely by its community, free for everyone.
- ✓Yours to keep. Your stable, cards, and horses are yours to export anytime. Nobody holds them hostage.
- ✓Open and honest. Built on the open-source Flycast emulator, and we tell you exactly how it works.
- ✓Works, or we help. Everything is tested to run out of the box, with a real community behind it.
- ✓Community-run, not gatekept. No single owner, no permission needed, no one controlling who gets to play.
- ✓For the love of the game. We keep DOC alive because we love it, not to sell you anything.
This is the DOC we all wanted: open to everyone, owned by no one, and here to stay.
Join the community on DiscordHow to Play
Playing is instant: the whole arcade runs in your browser. No download, no install, no setup, and nothing to keep updated. You don't need to be a computer person: open the page, take a seat, and you're racing. The quick steps below walk you through it.
What's running
| Two cabinets | An 8-player and a 6-player cabinet, both live. Anyone can watch the races as a guest, no account needed. |
| Open seating | Take any open seat to play. When both cabinets are full, join the line and the next open seat routes you straight in. |
| Arcade chat | An arcade-wide chat runs alongside the races, so you can talk between races and find people to play. |
New here? Our Discord community is the best place for help and to find people to race.
1
Open the Arcade
Go to play.johnreevesiii.com. It opens right in your browser, with nothing to install. You'll see the live cabinets and can watch the races straight away as a guest.2
Sign in (free)
To take a seat and play, sign in with a free account. It's quick, and it keeps your stable, so your horses are waiting for you every time you come back.Just want to watch? You don't need an account to spectate. The live
cabinets are open to everyone; signing in is only for taking a seat to race.
3
Take an open seat
Click an open seat on a cabinet to jump into the race in real time with the other owners. Both cabinets full? Join the line and the next open seat routes you straight in.4
Race with your stable
Make a new horse or bring one from your stable, and you're off. Use the arcade-wide chat to talk between races and find people to play. That's it, you're racing!Controls (keyboard)
When you're in a seat, these are the game's controls:
| Arrow keys | Move / choose |
| Enter | Start: create a horse / confirm |
| Z | Button A |
| X | Button B: back / cancel |
| C | Button C (also whip your horse during a race!) |
| V | Button D |
| I | Insert Card: load a saved horse |
Your stable
Your horses live in your stable, tied to your free account, so they're waiting for you next time. Press Enter to make a new horse, or I to load one. Your cards are yours to export anytime, and the browser tools below let you manage, edit and breed your whole stable.Browser Tools
Free companion tools that run right in your browser, nothing to install, and your data never leaves your PC.
Track Records · new — the online leaderboard
Beat a course record at home and post your time to the master record board. Run the DOC Record Uploader and it finds your save and submits your best times in one click, or use the web uploader and drag your save in. Per-race Top 10 for World Edition Rev C, Rev D, and DOC 2000 (DOC ’99 keeps no record board in its save, so it can’t be tracked), ties go to whoever submitted first, Japanese names supported. It's already in the Host Pack (run Submit My Records), or grab it below.
DOC Tools Suite · new — 20+ tools in one place
The whole toolbox, organized by what you want to do: Play & Plan (race simulator with win odds, foal predictor, feeding advisor, opponent scout, bond & personality), Theorycraft, and Mod & Inspect (card editor, ROM studio, string editor, card lineage). Includes The Hidden Rules — game mechanics decoded from the ROM that the game never tells you. Runs in your browser; load your own .card to analyze your horse.
Stable Management System
Opens automatically with the game. Organize your stable, create & edit horses, and drop any of
them onto a player station, no card-reader needed. Hover for a quick view, keep retired
sires & dams for breeding, import/export as .raw, full katakana support.
DOC Breeder Studio
Plan your stable: browse every CPU horse across all four versions, see each one's surface, distance, running style and standout abilities, and breed any sire & dam to project the foal before you spend a credit. ROM-verified data; Japanese names in katakana with English.
DOC ROM Studio · for tinkerers
Go deeper and edit the game's built-in data: the 244 CPU horses & stats, breeding stock, race & track names, and on-screen text, then save it back as a valid ROM. Handles all four versions and edits the Japanese ones natively (Japanese text, romaji, optional translate).
Back Up a Physical Card · hardware guide
Have real DOC player cards? This step-by-step guide shows how to scan a physical card to a
.raw backup with an MSR206 magnetic reader/writer, with photos and a demo
video. Includes the downloads you need: the MSR206 write program and the Super Juicer
spreadsheet. (Step 1 is a small hardware mod; the rest is software.)
Help & Updates
If something doesn't work
| Page won't load | Refresh the page, and make sure you're on a current browser (Chrome, Edge or Firefox). |
| No open seat | Both cabinets are full. Join the line and the next open seat routes you in, or watch until one frees up. |
| Can't take a seat | Taking a seat needs a quick free sign-in. Watching the races doesn't. |
| Choppy or slow | The arcade streams live, so a steady connection helps; closing other heavy browser tabs can too. |
| Home rig setup | Get the Host Pack with /hostpack in our Discord; the hosting channel there is where setup questions get answered fast. |
Still stuck? Ask in our Discord and we're happy to help. New to the stable tools? The Owner's Manual has a full walkthrough.
Revision Notes
What changed in each update to the packs & tools. Newest first.
| 2026-07-26 | Japanese cards: full read & write, and JP breeding (SMS v2.6). The Japanese card format (DOC 2000 & DOC ’99) is now fully decoded from the game’s own card code, so a Japanese horse reads out exactly like a World Edition one — running style, all six externals, current + birth Speed/Stamina/Sharp, win/place/show, hearts, G1 titles, retirement, earnings, turf/dirt aptitude, coat and personality. DOC ’99 is fully supported (it uses a different card marker, now recognized), and the Breeding Lab works in Japanese: pair Japanese sires and dams (CPU roster or Studbook), generate a real foal card, and load it onto a Japanese cabinet — the created card is game-valid (checksum and all), confirmed loading in-game. The web card manager is v2.6. 日本版カード完全対応 — 読み取り・繁殖・出走まで。 |
| 2026-07-23 | Play at Home: Host Pack 1.0 + DOC Stable Link. A full arcade row on one PC: the two-screen race board plus 4, 6, or 8 seats, all four game versions in one download, and a setup screen that asks one question. The boards boot and link on their own; rental horses at every seat with no account; record tables start fresh so your names fill your own big screen, with Submit My Records feeding the master board. Its free companion DOC Stable Link (download) turns every seat into a card reader for the online stable: players approve a seat code on their phone at play.johnreevesiii.com/seat-link and their own horses ride at that seat, saving home through the same server checks as every cabinet in the lobby. The Host Pack is distributed in our Discord (type /hostpack), and this page gained the Play at Home section. |
| 2026-07-25 | Card manager: Japanese cards fully decoded (SMS v2.3). The Stable Management System now reads the whole Japanese card, not just the name: hovering a DOC 2000 / DOC '99 horse shows its sex, current and birth internal stats, and retired status, decoded straight from the card. Full-length 9-character names now read correctly (they previously ran into the sire field), and a detection bug is fixed where a Japanese card saved on a seat that previously held a World card was mistaken for a World card. The public web card manager is updated to v2.3; the downloadable packs still bundle the earlier editor and will pick this up on their next rebuild. |
| 2026-07-02 | Card manager: Japanese horse names now show in katakana (SMS v2.2). In the Stable Management System, horses on Japanese cards (DOC 2000 / '99) now display their names in katakana across the station, stable, shared-pool and USB lists, instead of appearing as garbled symbols. Card recognition already read the Japanese names correctly in the hover details; now the list labels match. US cards are unchanged. The Card Suite Add-On and the public web card manager are updated to v2.2; the 4-Player, 8-Player and Tournament Edition packs still bundle the earlier editor and will pick this up on their next rebuild. Just re-download the Add-On or refresh the web tool. |
| 2026-06-27 | Play Online has launched: the full DOC Arcade. The online game has moved out of beta to its new home, a single front door for the arcade at play.johnreevesiii.com. Watch the live cabinets, sign in with a free account, and take an open seat to race in real time with your stable. It now runs two cabinets (an 8-player and a 6-player) with a shared line that routes you into the first open seat when both are full, plus an arcade-wide chat. The old play4 beta link and its Beta Results page are retired. Nothing to download: just visit play.johnreevesiii.com. |
| 2026-06-24 | Multiplayer Beta now seats 6 players. The shared Multiplayer Beta cabinet (then on the old play4 box) grew from 4 player stations to 6, so more owners can race together in real time. The live Beta Results page tracked all 6 seats. (The beta has since moved to play.johnreevesiii.com; the old play4 box and its results page are retired.) |
| 2026-06-23 | DOC Myths: Rev D footnote on the turf myth. The "Good to Soft" / turf myth now notes that the answer is version dependent. On Rev C the going is one shared scale (turf can be Good to Soft); the later Rev D build rebuilt the going to be surface-specific (turf: Firm/Good/Soft/Yielding, dirt: Fast/Good/Heavy/Muddy) and removed "Good to Soft" entirely. Page-only change; nothing to re-download. |
| 2026-06-23 | DOC Myths: Myth #2 on beer. The DOC Myths page gains a second entry. Settled from the ROM: beer is a real, fully coded food the game even writes special code for, and its stat-growth values are all zero (the only food like that), so it boosts nothing. Still open: whether beer is actually served in Rev C, since the game computes that at runtime. Verdict: Open, with a community call to action. Page-only change; nothing to re-download. |
| 2026-06-23 | NEW: DOC Myths page. A new DOC Myths page tests common Derby Owners Club claims against the actual arcade ROM, in a claim, evidence, verdict format, with a shareable link for each myth. The first entry settles whether a turf race can be rated Good to Soft: it can, and there is no turf exclusion anywhere in the game. Find it in the nav as DOC Myths. Page-only change; nothing to re-download. |
| 2026-06-20 | Beta Results page now linked. The Multiplayer Beta section linked to a live Beta Results page: frames streamed, data delivered, play-hours, peak players at once, seat popularity, and an hour-by-hour breakdown, refreshed automatically. (Retired with the play4 beta box; the arcade now lives at play.johnreevesiii.com.) |
| 2026-06-19 | Multiplayer Beta is live. Play Derby Owners Club online with other people right in your browser, no download or setup: a shared 4-player cabinet you can jump into with your stable. See the Play Online section at the top of the page. (The beta launched on the old play4 box and has since moved to play.johnreevesiii.com.) |
| 2026-06-12 | Controls now shown as a labeled panel image. The Controls section on this page and in the full Manual now includes a picture of the cabinet control panel with each key labeled (arrow keys to move, Enter to start, Z is Button A, X is Hold, C is Whip, and I inserts a card), so the keyboard mapping is easy to see at a glance. Nothing to re-download: just refresh the page. |
| 2026-06-12 | Station Manager standalone updated to SMS v2.1. The standalone download now carries the same helper-recovery fix Tournament Edition received on 2026-06-11: if the helper window is closed or stopped, the manager shows a clear banner ("Card Suite helper is not running"), pauses live station updates, and reconnects on its own when you relaunch it from Start-Station / Start-Rig, instead of failing silently with a "failed to fetch". Custom and multi-PC setups start and stop the helper by hand more than the packs do, so this fix matters most here; the standalone and Tournament Edition now match at SMS v2.1. Everything else is unchanged: the 4-Player and 8-Player packs and the Card Suite Add-On need nothing. Download the standalone (≈0.2 MB). |
| 2026-06-11 | Tournament Edition: clearer recovery when the card helper stops (SMS v2.1). The Tournament Edition's Station Managers now handle the helper window being closed or stopped gracefully. If loading a horse to a station stops working because that window was shut, the manager shows a clear banner ("Card Suite helper is not running"), pauses live station updates, and reconnects on its own the moment you relaunch the helper from its launcher, instead of failing silently with a "failed to fetch". Building and downloading cards keeps working the whole time. This update is in Tournament Edition only. The 4-Player and 8-Player packs, the Card Suite Add-On, and the Station Manager standalone are unchanged, so if yours is working well there is nothing you need to do. |
| 2026-06-10 | NEW DOWNLOAD: Tournament Edition + DOC II self launcher. A third pack joins 4 Players and 8 Players (both unchanged) — a 4-player pack built for groups. Station Managers (SMS v2.0): every player station gets its own card manager — a private stable per player, a shared pool all stations trade through, and USB stick support (it reads and writes the same card_library folder as the community's standalone card manager, so cards move freely between both tools). One-physical-card rule: moving an active horse really moves it — no duplicate horses on the money boards — while retired sires & dams copy, so everyone can breed from a shared stud book. Tournament mode: an owner PIN locks any station to "manage" (load, organize and share only — no creating or editing horses), and Setup-Tournament.ps1 locks the whole rig with a seeded stud-book pool in one shot. DOC II included: Play - DOC II (Japanese).bat runs Derby Owners Club II with the full main + 4 satellite link on a newer emulator build with DOC II multiboard support — its horse cards are still being reverse-engineered, so DOC II runs without card managers for now. Smarter windows: the launcher places the main board's two screens (Main L + Main R) side by side automatically and labels the satellites Sat 1–4; layout is written into each board's config before launch so windows open in place. Multi-PC play: a "More Play Options" folder launches any subset of boards (Main only, single satellites, Sats 1–4) so one PC can host the Main while each player PC runs just its own station. Full details ship in the pack's RELEASE NOTES file. |
| 2026-06-10 | Station Manager standalone (SMS v2.0). The per-station card manager from Tournament Edition is also a small standalone download for custom Flycast setups and stations on separate machines: the helper + manager page, Start-Station / Start-Rig / Setup-Tournament launchers, a config example, and the full operator guide & spec. The original Card Suite Add-On remains the right add-on for the classic 4-Player / 8-Player packs. |
| 2026-06-09 | Why board times end in .0 or .5. The Track Records guide now explains the timing: the cabinet saves each record on a coarse ~1/20-second clock, so the board shows the exact record the machine kept — about 0.03–0.05 s slower than your in-game RESULT screen, and that finer time is never saved. The board stays faithful and rankings stay fair. It also asks whether you’d want a photo + OCR option for exact times — weigh in on our Discord. |
| 2026-06-08 | DOC 2000 added to the board; DOC ’99 can’t be. Track Records now covers three versions: World Edition Rev C, World Edition EX Rev D, and DOC 2000 (Japanese course and horse names shown in full). A timing fix also corrected the Rev D record times. DOC ’99 stays off the board: the 1999 original keeps no per-course record board in its save, so there is nothing to read. |
| 2026-06-07 | Track Records leaderboard (new). Beat a course record at home and post it to the master board at Track Records. Submit with the new DOC Record Uploader (it finds your save and uploads in one click) or the web uploader. Per-race Top 10 for each supported version, ties to whoever submitted first, with Japanese names supported. It's now included in the 4-Player and 8-Player packs (run Submit My Records in your pack folder), and downloadable standalone from the Track Records card below. Full walkthrough: the step-by-step guide. |
| 2026-06-06 | Back up a physical card (new guide). A new step-by-step guide covers scanning a real DOC player card to a .raw backup with an MSR206 magnetic reader/writer, with photos and a demo video, plus downloads (the MSR206 write program and the Super Juicer spreadsheet). Find it in the nav as Card Backup or in Browser Tools. |
| 2026-06-06 | Tools Suite User Guide. A new User Guide explains every tool in the Suite in detail: what it is, why it helps, and step-by-step how to use it, with a table of contents. It is linked from the top of the Tools Suite page. |
| 2026-06-06 | Breeding Lab fixes. In the Breeding Lab, the Japanese versions now show horse names in katakana (with romaji in parentheses) instead of romaji alone, so they are easy to read. The best-mate finder is now clearly labeled as within the selected version only: each version is a separate game, so suggested mates always come from the same region. Just refresh the Suite. |
| 2026-06-06 | Tools Suite polish. Small fixes across the Tools Suite: in the Race Lab the "Your horse" stat boxes are wider and centered so values like dirt 100 no longer clip; on the launcher the colored badges now mean one consistent thing (green = no files, amber = reads your files, red = writes/edits your files), with plain category labels shown as outline-only; the whole tab buttons are clickable, the footer links are easier to read, and the Race Lab table has light row striping. Just refresh the Suite. |
| 2026-06-06 | Every Tools Suite tool now reads both horse-file formats. The online Tools Suite tools that open a horse — the Race Lab, Breeding Lab, Bond & Personality advisor, Card Differ and the Feeding Advisor — now accept both the new .card and the older .raw card-reader export, and read exactly the same horse from either. (The Feeding Advisor can now load a horse to show its current Speed/Stamina/Sharp and a projected total after your feeding plan.) Japanese (DOC 2000/'99) cards are now recognized too: they carry identity and pedigree only (stats live in the cabinet), so the tools say so plainly instead of rejecting the file. Also fixed a readability glitch where the Breeding Lab's top control bar showed up as a hard-to-read green; it's back to the dark toolbar. Nothing to re-download — just refresh the Tools Suite. |
| 2026-06-06 | Personality is now preserved exactly when you save a card. An earlier version of the Stable Management System could quietly change a horse's personality when you saved a card — if its value wasn't one of the five presets in the dropdown (for example 100 became 80), even if you never touched the personality field. Personality controls how a horse reacts to you after a race, so this could shift a horse's behavior without you knowing. Fixed: the editor now keeps the exact value and only changes it when you deliberately pick a different personality. (The card's field positions were always correct — this was a save-time rounding bug.) All three downloads were rebuilt; re-download a pack or grab the Card Suite Add-On to get it. |
| 2026-06-03 | Saving cards is clearer, and cards now save by horse name. The Save .card (to PC) button now names the file after the horse and the game version (e.g. Gold Queen (Rev C).card) instead of a generic name, so saved cards never overwrite each other or get mixed up, even across Rev C, Rev D and the Japanese versions. A new Save both button downloads the .card and the .RAW in one click. Loading any .card or .raw reads the horse from the data and tells you who it is, so the two formats are freely interchangeable. The Owner's Manual (Section 7) now has a clear step-by-step for saving and bringing horses back. Re-download a pack or grab the Card Suite Add-On to get it. |
| 2026-06-03 | DOC ROM Studio added. A new free in-browser ROM editor for tinkerers: open the program ROM and edit the game's built-in data — the 244 CPU horses and stats, breeding stock, race & track names, and on-screen text — then save it back as a valid 4 MB ROM. Covers all four versions, including native editing of the Japanese versions (DOC 2000 & DOC '99): it reads and writes Japanese text, shows romaji, and has an optional bring-your-own-key translation helper. You supply your own ROM; it all runs offline in your browser. See the guide for a step-by-step (with a detailed Japanese walkthrough). |
| 2026-06-03 | Japanese card editing in the Stable Management System. You can now load a Japanese card (DOC 2000 or DOC Original) and rename the horse with a built-in katakana keyboard, and set its sire and dam from a dropdown of all 164 authentic breeding names pulled straight from the arcade ROMs. The card's ID, format markers and data are preserved; only the name and pedigree are rewritten. (Japanese horse stats live in the cabinet, not on the card, so this edits the horse's identity: name and pedigree.) Both packs and the Card Suite Add-On were updated; re-download to get it. |
| 2026-06-01 | DOC Breeder Studio added. A new free in-browser breeding planner covering all four versions: a foal stat calculator, a per-horse analyzer (surface, distance, running style, standout abilities), and a side-by-side breed & compare view. Every horse's stats are verified against the arcade ROMs, and the Japanese versions show names in katakana with English. See the Browser Tools section above to open it. |
| 2026-05-31 | Card suite auto-start fix. Fixed a case where the Stable Management System would not open by itself if your game folder sat in a path with a space in it (a common reason it "won't start on its own"). Both packs and the Card Suite Add-On were updated. If yours still does not auto-open, re-download, or grab the Add-On (say Yes to replace _launch.ps1). There is also a Tools\Test-Card-Suite.bat you can double-click to start it in a visible window. See the manual's troubleshooting. |
| 2026-05-31 | Race program now resumes after a reboot. Both the 4-Player and 8-Player packs were rebuilt with the latest Flycast fix: when you close the game and reopen it, it picks up the race program where you left off (the same race section and standings) instead of snapping back to the first race. Also fixed in the Stable Management System: horses whose name has an apostrophe (like O'Brien) now work correctly on the stable buttons. Re-download your pack for the full fix, or grab the tiny Card Suite Add-On for just the name fix. |
| 2026-05-31 | 8-Player pack added. A new 8 Players download joins the original (now labeled 4 Players): a main race screen plus 8 player stations (9 windows), a full arcade row. The Stable Management System scales to 8 stations and auto-refreshes live as you play. Pick 4 or 8 at the top of this page. |
| 2026-05-31 | Stable Management System. Renamed from the Card Editor. New: organize your stable with drag-to-reorder and quick sorts; hover any horse for an at-a-glance card (sire/dam, leg type, sex, personality, color, dirt, stat bars); retired horses split into Sires ♂ and Dams ♀ with breeding badges; a tidy stable cap (10 active + 2 sires + 2 dams) with live counters; import / export horses to your PC as .raw files; and full Japanese (katakana) horse-name support. The Owner's Manual was rewritten to cover all of it. |