# Rotation — the URL is the API This page keeps the whole lineup in the URL fragment (the part after `#`). Nothing lives on a server, so you don't need this site, a browser, or any API to read or write a lineup. If you can build JSON and base64, you can set a lineup and hand the coach a link. ## Links ``` https://tools.marplecoaching.com/rotation/#r= editable https://tools.marplecoaching.com/rotation/#v= read-only view https://tools.marplecoaching.com/rotation/#g= read-only, groups only — no minutes ``` `#g=` is the one to send to players: who's in goal each half and who rotates with whom, with the minutes left out. The same payload works in all three. `payload` is base64url of UTF-8 JSON: standard base64 with `+` → `-`, `/` → `_`, trailing `=` stripped. Browsers never send the fragment with a request, so names stay out of server logs — but anyone holding a link can decode it, so treat a link like the roster it contains. ## The JSON ```json { "game": 60, "slots": { "GK": 1, "CB": 2, "FB": 2, "WB": 0, "DM": 1, "CM": 0, "AM": 2, "W": 0, "ST": 1 }, "groups": [["CB", "FB"], ["DM", "AM"], ["ST"]], "k1": 8, "k2": 9, "players": [ { "n": "Ada", "p": ["CB"], "g1": null, "g2": null, "out": false }, { "n": "Bex", "p": ["FB", "CB"], "g1": null, "g2": null, "out": false } ] } ``` - **game** — whole-game minutes, 10–120. - **slots** — how many of each position are on the field at once. Codes, back to front: `GK` keeper, `CB` centerback, `FB` fullback, `WB` wingback (the wide player in a back three), `DM` defensive mid, `CM` central / box-to-box mid (the 8s), `AM` attacking mid, `W` winger, `ST` striker. `GK` is 0 or 1 (3v3 and 4v4 play without one), the rest 0–4. A code you leave out is 0. A 9v9 4-3-1 is the block above; the page's presets, for reference: | | GK | CB | FB | WB | DM | CM | AM | W | ST | |---|---|---|---|---|---|---|---|---|---| | 7v7 2-3-1 | 1 | 2 | | | 1 | | 2 | | 1 | | 9v9 4-3-1 | 1 | 2 | 2 | | 1 | | 2 | | 1 | | 9v9 3-2-3 | 1 | 3 | | | 2 | | | 2 | 1 | | 11v11 4-3-3 | 1 | 2 | 2 | | 1 | | 2 | 2 | 1 | | 11v11 4-4-2 diamond | 1 | 2 | 2 | | 1 | 2 | 1 | | 2 | | 11v11 4-2-3-1 | 1 | 2 | 2 | | 2 | | 1 | 2 | 1 | | 11v11 3-5-2 | 1 | 3 | | 2 | 1 | 2 | | | 2 | | 11v11 3-4-3 | 1 | 3 | | 2 | | 2 | | 2 | 1 | Anything else is a custom formation: set the counts you want. A saved team (`/team/agent.md`) carries the same `slots` object as its default formation; a lineup opened from a team starts in it. - **groups** — the rotation groups: arrays of position codes. Together they must cover every field position that has spots, each position in exactly one group. Any mix is legal — `["FB", "W"]` is a fine group. A position left out of every group is auto-adopted into a group holding one of its linemates; don't rely on that, write it explicitly. The page keeps groups in pitch order, back to front by the deepest position each holds, and moves the per-player overrides along with them — so write them in any order, but expect them back sorted. - **players** — up to 40. Per player: - `n` — name, ≤30 characters. - `p` — positions they can play, best first. The first one with spots in this formation picks their default group. `GK` anywhere in the list makes them a keeper candidate. The first two are her main and backup spots: put her in a group holding neither and the page marks it as a new role for the day ("usually CB"). - `g1`, `g2` — group override for the 1st / 2nd half: an index into `groups`, or `null` for automatic. - `out` — `true` means absent today; they're ignored everywhere. - `lock` — `true` means the coach has decided on her: the page draws her chip solid, won't drag it, and counts the rest as "still to place". When the page locks a player it first writes her current placement into `g1`/`g2` (or `k1`/`k2`) so a regroup can't move her; do the same when you set it. Leave it out when it's off. - **k1**, **k2** — who's in goal each half: an index into `players`, or `null` for automatic (the first / second available player listing `GK`). The same index in both means one keeper all game. A keeper's off-goal half is played with their normal group like anyone else. ## The math the page will show Per half (`time = game ÷ 2`), then summed for the day: - group minutes each = `time × spots ÷ players in the group`, capped at `time` - a keeper's goal half counts as full minutes - even share = `time × total field spots ÷ total field players` — the benchmark; the page flags groups more than ~5 min off it and suggests movers who list a position in a starved group - `players − spots` = how many of that group are off at any moment (at 4+ the page says to swap in waves of 2–3) Run these yourself before answering: aim every group near the even share unless the coach asked for something else, and call out any group with players = spots — those play every minute. ## Worked example 12 players (one out), 9v9 4-3-1, 60 minutes, keepers Posy and Quinn splitting halves — both list `ST`, so each plays their field half as a forward: ``` https://tools.marplecoaching.com/rotation/#r=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 ``` What that decodes to, per half: Defenders (Ada, Bex, Cleo, Dot, Fern) 5 for 4 spots → 24 min each; Midfield (Ida, Juno, Kit) 3 for 3 → 30, no rotation; Forwards 2 for 1 → 15 each half. Even share 24. Day totals: defenders 48, midfielders 60, Rae 30, each keeper 45 (30 in goal + 15 at ST), Tess out. ## Recipe for setting a lineup 1. Decode the coach's link if you got one; otherwise start from the schema. 2. Edit: availability (`out`), positions, groups, keepers, per-half overrides. 3. Do the math above and sanity-check the plan before showing it. 4. Encode and reply with the `#r=` link — plus a `#v=` link if it's going on to an assistant coach, or `#g=` if it's going to the players (groups, no minutes). Bad values never error — they're clamped or fall back to automatic, so a sloppy payload still loads, just maybe not as you intended. Decode your own link once to confirm it says what you meant.