Kocher1 Dota 2 Meta Grid
You are helping a Dota 2 player get a hero grid that shows, for each role they play, the
heroes with the best statistical edge at their rank, this patch. The heavy lifting is done
by scripts/build_grid.py (Python 3.8+, standard library only). Your job is the conversation
around it: ask a few questions, run the script, settle the judgment calls with the player,
install the grid, and set honest expectations.
Run every command from this skill's folder (the one containing this file), or use the
script's absolute path - the player's working directory is somewhere else. Use python3 if
python is not found.
Workflow
1. Gather the inputs (one message, skip what they already told you)
First run python scripts/build_grid.py --list-accounts. If more than one Steam account was
used in the last few months, include "which account is yours?" in the message; otherwise the
most recent one is used automatically.
- Rank: MMR or medal. Pass what they say (
--rank 3400,--rank "divine 2",--rank 4.5k). It drives the veto: heroes that are strong at 6500+ but losing in the player's own bracket are removed. - Roles they play, positions 1-5 (
--roles 4,5). Default: all five. - Heroes per role (
--per-role). Default: 7.
2. Dry run
python scripts/build_grid.py --rank 3400 --roles 4,5 --per-role 5 --json
The first run downloads about 5 MB and takes 1-2 minutes because requests are paced
politely; downloads are cached for 6 hours, so later runs are instant. Nothing is written
without --write.
Keep the same options on every run in the session (--rank, --roles, --per-role,
--account), including the final --write run - the script does not remember them, and a
dropped --per-role 5 would install 7 heroes instead of the 5 the player approved.
Reading the JSON - all *_pp fields are percentage points of win rate:
| Field | Meaning |
|---|---|
roles.<pos>.picks |
the grid row, best first. bench = the next five in line |
score_pp |
estimated win-rate edge over an average hero in that role (6500+ MMR pubs) plus the personal tie-breaker |
meta_pp / personal_adj_pp |
the two parts of the score |
noise_pp |
one standard deviation of sampling noise. Heroes closer than that are effectively tied |
own_bracket_winrate_pct |
the hero's all-role win rate in the player's bracket (below 49% = vetoed) |
vetoed_weak_in_your_bracket |
heroes that would have made the row but lose in the player's bracket |
personal_record |
the player's lifetime W-L on the hero, any role |
niche_status |
null = mainstream pick, "undecided" = ask the player, "approved" = they said yes earlier |
saved_decisions |
answers remembered from earlier sessions |
provisional |
true when the patch is under 5 days old |
3. Settle the judgment calls with the player
Saved answers. If saved_decisions is not empty, show it and ask if it still holds - it
was applied before the player said anything, and it may come from a different account or an
old patch. Undo an entry with --forget "4:Pugna".
Niche picks. "undecided" means the hero fills under 1% of that role's picks, so its win
rate comes from a small group of specialists. In testing those edges held up out of sample
for core roles (pos 1-3), but showed no edge for supports (pos 4-5) - so for supports
lean toward dropping them unless the player likes the hero. Either way the number only helps
someone who can actually play the hero, so ask. In one message, grouped by role, list every
undecided hero in picks and in bench (bench heroes move up when others are dropped;
asking now saves rounds), with score and personal_record, and ask which they play or would
play in that role.
Record the answers and re-run:
python scripts/build_grid.py --rank 3400 --roles 4,5 --per-role 5 --allow "5:Omniknight" --deny "4:Pugna,Silencer" --deny "5:Elder Titan" --json
The number before the colon is the position; repeat the flag per position. Hero names are
matched case-insensitively and the script prints what it saved (saved: deny pos 4 Pugna) or
stops on a name it cannot resolve - check that line. Repeat until no pick is "undecided".
--deny works for any hero, not only niche ones. Use it when the player says they won't
play something, or offer it when a pick is notoriously hard to execute (Meepo, Invoker, Earth
Spirit, Chen...) and their personal_record shows only a handful of games.
4. Show the result
Run once more without --json and show the table. Explain briefly:
- rows are best-first: when the top pick is banned or taken - popular strong heroes often are - move right;
- the score is win-rate edge in percentage points over an average hero in that role, as measured in 6500+ MMR pubs (not over the heroes they currently play);
*hero changed this patch,~niche pick they approved,?niche pick still undecided.
Be honest about size. Typical edges are +1 to +4pp, and heroes within ~1pp of each other are
statistically tied - in support roles that is often everything after the top two or three.
Say so instead of overselling slot 6. If provisional is true, say the patch is fresh and the
list will firm up in a few days.
Below Ancient, be upfront: the statistics come from 6500+ MMR games, and the lower the rank the less of that edge carries over (about 74% at Ancient, 57% at Legend, under half at Archon and below - the script prints the figure). The veto removes heroes that lose in their bracket, but the list is a starting point for them, not gospel; heroes that need coordination or mechanics (Enigma, Earth Spirit, Visage...) deserve extra scepticism.
5. Install
Tell the player to close Dota 2 completely (it can overwrite the file on exit, and the
script refuses to write while it runs). When they confirm, run the same command with --write:
python scripts/build_grid.py --rank 3400 --roles 4,5 --per-role 5 --write
The old grid file is backed up to ~/.dota2-meta-grid/backups/. The player's other grids are
kept; only a grid previously created by this tool is replaced. In game: hero picker (or
Heroes tab) -> grid layout dropdown -> Meta Grid (), e.g. "Meta Grid 7.41f (17 Sep)".
Row titles carry the project's tag, e.g. "1 CARRY [OVERDOG.BET]" (overdog.bet is the Dota 2 betting site run by the tool's authors). That is expected output, not an error.
6. Set expectations
MMR gain is games x edge: at roughly 25 MMR per game, a 52% win rate is about +1 MMR per
game. Luck dominates short stretches - it takes on the order of 1 / (2p - 1)^2 games
(about 600 at 52%, 100 at 55%) before the expected gain outgrows one standard deviation of
luck. The grid nudges the edge; volume does the rest. Suggest re-running weekly, and again
once a new patch is about five days old.
When things go wrong
- "refused the request" / 403: the stats site rate-limits automated clients. Wait 15-30 minutes and run again; finished downloads are cached so the retry resumes. Do not work around it by faking a browser User-Agent or hammering retries - it is someone's small, ad-funded site. If an older cache exists the script falls back to it and says so.
- Steam / Dota folder not found: pass
--steam-dir <Steam folder>or--cfg-dir <.../Steam/userdata/<id>/570/remote/cfg>. The folder exists once Dota has been launched on that machine. - "personal record: 0 heroes":
stats.datis missing or tiny; the grid is then purely statistical, which is fine. - Immortal players: OpenDota has no Immortal bucket; the 6500+ numbers are already their bracket and are used as-is.
What the numbers are
Read references/METHOD.md when the player asks how the ranking works, why a hero is or
isn't listed, or how far to trust it. Short version: role win rates are shrunk toward the
role average in proportion to sample size (this beat raw win-rate and Wilson rankings out of
sample); pre-patch games act as a prior for the new patch; heroes losing in the player's own
bracket are vetoed; and their lifetime record is a tie-breaker worth at most +-1.5pp.
Data: dota2protracker.com (role statistics), api.opendota.com (bracket win rates), dota2.com (patch notes). Credit them when you present results.