# Y Combinator stacks by batch year, 2012 to 2026

One row per batch year and tool.

## Columns

- `year`: the YC batch year, 2012 to 2026.
- `base`: Y Combinator domains scored in that batch year.
- `tool_slug`: the Installmap fingerprint slug.
- `tool_name`: the brand name.
- `users`: domains in that batch year carrying the tool.
- `share`: `users` divided by `base`, as a fraction between 0 and 1.

## Denominators

The base column is the denominator for every share in the same row. Per-year
bases run from 69 (2013) to 641 (2026). The blocks used in the report are
2012-17 (840 domains), 2022 (567) and 2025-26 (1,248).

Of the 5,386 Y Combinator domains scored out of 6,133 on the list, 5,175 carry
a batch year between 2012 and 2026 and appear in this file.

## Licence

Data: CC BY 4.0, Installmap, 2026-09-04.
Source: Installmap, September 2026.